Auxiliary liver transplantation with arterialization of the portal vein for acute hepatic failure

Six adult patients suffering from acute hepatic failure and with a high urgent status underwent heterotopic auxiliary liver transplantation. In four of these patients, the portal vein of the liver graft was arterialized in order to leave the native liver and the liver hilum untouched and to be able to place the liver graft wherever space was available in the abdomen. The arterial blood flow via the portal vein was tapered by the width of the anastomosis. Two patients died, one of sepsis on postoperative day 17 (POD), the other after 3 months due to a severe CMV pneumonia. There were no technically related deaths. The native liver showed early regeneration in all cases. In one patient, the auxiliary graft was removed 6 weeks after transplantation. Four weeks later, he had to undergo orthotopic retransplantation due to a recurrent fulminant failure of the recovered native liver. This patient is alive more than 1 year after the operation. We conclude that heterotopic auxiliary liver transplantation with portal vein arterialization is a suitable approach to bridging the recovery of the acute failing native liver. Received: 15 September 1997 Received after revision: 4 February 1998 Accepted: 2 March 1998     

Improved technique of heterotopic auxiliary rat liver transplantation with portal vein arterialization

BACKGROUND AND AIMS: In acute, potentially reversible hepatic failure, auxiliary liver transplantation is a promising alternative approach. Using the auxiliary partial orthotopic liver transplantation (APOLT) method--the orthotopic implantation of auxiliary segments--most of the technical problems (lack of space for the additional liver mass, the portal vein reconstruction, and the venous outflow) are avoided, but extensive resections of the native liver and the graft are necessary. Erhard described the heterotopic auxiliary liver transplantation (HALT) with portal vein arterialization (PVA). Initial clinical results demonstrated that an adequate liver function can be achieved using this technique. We developed and improved a technique of HALT with flow-regulated PVA in the rat to perform further investigations. The aim of this paper is to explain in detail this improved experimental surgical technique. MATERIALS AND METHODS: Liver transplantations were performed in 122 male Lewis rats: After a right nephrectomy, the liver graft, which was reduced to about 30% of the original size, was implanted into the right upper quadrant of the recipient's abdomen. The infrahepatic caval vein was anastomosed end-to-side. The donor's portal vein was completely arterialized to the recipient's right renal artery in stent technique. Using a stent with an internal diameter of 0.3 mm, the flow in the arterialized portal vein was regulated to achieve physiologic parameters. The celiac trunk of the graft was anastomosed to the recipient's aorta, end-to-side. The bile duct was implanted into the duodenum. RESULTS: After improvements of the surgical technique, we achieved a perioperative survival of 90% and a 6-week survival of 80% in the last 112 transplantations. CONCLUSION: We developed a standardized and improved technique, which can be used for experiments of regeneration and inter-liver competition in auxiliary liver transplantation. Furthermore, this technique is suitable for the investigation of the influence of portal vein arterialization and portal hyperperfusion on liver microcirculation, function, and morphology.     

Outcome and Hepatic Hemodynamics in Liver Transplant Patients with Portal Vein Arterialization

Few cases of successful portal vein arterialization in orthotopic and auxiliary liver transplantation have been reported. AIM: To evaluate the effect of portal vein arterialization on hepatic hemodynamics and long-term clinical outcome in three patients undergoing liver transplantation. METHODS: Two patients with extensive splanchnic venous thrombosis received an orthotopic liver transplant and one with fulminant hepatic failure received an auxiliary heterotopic graft. Portal vein arterialization was performed in all cases. RESULTS: One patient died 4 months after transplant and two are still alive. Auxiliary liver graft was removed 3 months post-transplant when complete native liver regeneration was achieved. Immediate post-transplant liver function was excellent in all cases. Only one patient developed encephalopathy and variceal bleeding owing to prehepatic portal hypertension secondary to arterioportal fistula 14 months after transplant. He was successfully treated by embolization of the hepatic artery. Hepatic hemodynamic measurements demonstrated a normal pressure gradient between wedged and free hepatic venous pressures in all cases. Liver biopsy showed acceptable graft architecture in two cases and microsteatosis in one. CONCLUSIONS: Liver transplantation with portal vein arterialization is an acceptable salvage alternative when insufficient portal venous flow to the graft is present. The double arterial supply does not imply changes in hepatic hemodynamics, at least in the early months post-transplant.     

Auxiliary liver transplantation: how to improve regeneration of the native liver by surgery

The technical factors which could influence regeneration of the native liver (NL) in auxiliary liver transplantation (ALT) for fulminant hepatic failure (FHF) are not well known. We studied NL regeneration according to the location of graft anastomosis in the recipient's portal system (superior mesenteric vein versus portal vein), and graft weight (50 % reduced-size versus full-size graft) in a rat model of ALT with 80 % reduction of the NL, and graft arterialization. NL regeneration was significantly more obvious when the graft was anastomosed on the recipient's superior mesenteric vein, thus establishing venous flow to the NL from the pancreas, the spleen, and the stomach, and when a full-size graft was used. The influence of portal venous flow on NL regeneration, assessed by [³H]-thymidine incorporation, was measurable as early as day 2. Both technical variables in combination resulted in significantly greater regeneration (ratio weight of NL/body weight at day 30: 2.32 ± 0.68 % versus 1.21 ± 0.63 % respectively, P = 0.02). Early preservation of portal flow to the NL is advisable to maximize NL regeneration in ALT. In any case, this regeneration is not impeded by the use of large auxiliary grafts. Received: 11 February 1999 Received after revision: 29 July 1999 Accepted: 1 September 1999     

20%小体积的大鼠肝脏移植模型

目的 应用显微外科技术建立20%小体积移植物的大鼠原位肝脏移植模型.方法 原位移植建立20%小体积大鼠肝脏移植模型.雄性Lewis大鼠40只,供体20只,受体20只.供肝经门静脉用4℃ UW液灌注.肝上下腔静脉用端端吻合连续缝合的方法.肝下下腔静脉和门静脉分别用套管方法固定.套叠缝合法重建肝动脉.胆管重建采用内支架管端端连接的方法.观察移植物的存活率.免疫组化检测肝细胞摄取溴脱氧尿核苷的情况.结果 共施行肝脏移植手术20例,移植手术成功率为100%.20%小体积肝脏移植物的存活率为93.8%(＞14 d).组织学检查移植后的肝脏组织结构良好.移植术后72 h溴脱氧尿核苷染色阳性的肝细胞计数明显增多.结论 20%小体积大鼠肝脏移植物可启动完成移植后的肝脏再生.显微外科技术是移植模型成功的关键.该模型稳定性强,适合于部分肝脏移植领域的基础研究.     

猪辅助性部分肝移植模型制作及比较

目的建立猪的辅助性部分肝移植模型,观察其肝功能和术中血流动力学变化。方法 24头健康良种家猪,体质量23-30 kg,被随机分为供体(n=12)和受体(n=12)。气管插管 全麻,硫喷妥钠静脉维持。移植前切除受体肝左叶,供肝右叶作为植入肝。预实验2例行经体位转流的原位辅助性部分肝移植,对照组(5例)行简易转流下的原位辅助性部分肝移植。模型组(5例)行异位辅助性部分肝移植, 供肝被植入受体肝下间隙,供肝肝上下腔静脉与受体肝下下腔静脉端侧吻合,供肝门静脉与受体门静脉行端侧吻合,供肝肝动脉与受体脾动脉行端端吻合。供肝胆总管置管外引流。结果预实验中行体位静脉转流的原位辅助性部分肝移植的2例受体在肝上下腔静脉阻断后很快陷入血流动力学紊乱死亡。5例行简易静脉转流的原位辅助性部分肝移植的受体,2例在24 h内死亡,1例28 h,2侧超过48 h。而模型组受体 5例中有4例存活超过24 h。AST,ALT指标手术开始至术后24 h呈持续升高。模型组术中血流动力学较其他组稳定。结论该辅助性肝移植模型简明易建且具有不需静脉转流等优点,为研究辅助性部分肝移植原肝和供肝功能及血流变化提供了理想的平台。     

Portal vein reconstruction in pediatric liver transplantation from living donors.

OBJECTIVE: The authors analyze the surgical pattern and the underlying rationale for the use of different types of portal vein reconstruction in 110 pediatric patients who underwent partial liver transplantation from living parental donors. SUMMARY BACKGROUND DATA: In partial liver transplantation, standard end-to-end portal vein anastomosis is often difficult because of either size mismatch between the graft and the recipient portal vein or impaired vein quality of the recipient. Alternative surgical anastomosis techniques are necessary. METHODS: In 110 patients age 3 months to 17 years, four different types of portal vein reconstruction were performed. The portal vein of the liver graft was anastomosed end to end (type I); to the branch patch of the left and right portal vein of the recipient (type II); to the confluence of the recipient superior mesenteric vein and the splenic vein (type III); and to a vein graft interposed between the confluence and the liver graft (type IV). Reconstruction patterns were evaluated by their frequency of use among different age groups of recipients, postoperative portal vein blood flow, and postoperative complication rate. RESULTS: The portal vein of the liver graft was anastomosed by reconstruction type I in 32%, II in 24%, III in 14%, and IV 29% of the cases. In children <1 year of age, type I could be performed in only 17% of the cases, whereas 37% received type IV reconstruction. Postoperative Doppler ultrasound (mL/min/100 g liver) showed significantly (p < 0.05) lower portal blood flow after type II (76.6 +/- 8.4) versus type I (110 +/- 14.3), type III (88 +/- 18), and type IV (105 +/- 19.5). Portal vein thrombosis occurred in two cases after type II and in one case after type IV anastomosis. Portal stenosis was encountered in one case after type I reconstruction. Pathologic changes of the recipient native portal vein were found in 27 of 35 investigated cases. CONCLUSION: In living related partial liver transplantation, portal vein anastomosis to the confluence with or without the use of vein grafts is the optimal alternative to end-to-end reconstruction, especially in small children.     

Functional portal flow competition after auxiliary partial orthotopic living donor liver transplantation in noncirrhotic metabolic liver disease

Auxilliary partial orthotopic liver transplantation (APOLT) was introduced initially as a tentative or permanent support for patients with potentially reversible fulminant hepatic failure and has extended its indication to congenital metabolic disorder of the liver that has otherwise normal functional integrity. Postoperative management of APOLT is complicated because of functional portal flow competition between the native and graft liver. The native portal vein diversion to the graft is sometimes indicated to prevent functional competition; however, it is still an open question whether this technique can be theoretically indicated for APOLT patients. The authors report a on patient with ornithine transcarbamylase deficiency who received APOLT from a living donor without native portal vein diversion. Because of functional portal vein competition between the native and graft liver, the patient had to have portal vein diversion, portal vein embolization, and finally native hepatectomy to induce the graft regeneration after APOLT. After the experience of the current case, primary portal vein diversion for APOLT with noncirrhotic metabolic liver disease patients to prevent functional portal flow competition is recommended.     

Improved microcirculation of a liver graft by controlled portal vein arterialization

BACKGROUND: The clinical results of portal vein arterialization (PVA) in liver transplantation are controversial without a standardized portal flow regulation. The aim of these experiments was to perform a flow-regulated PVA in liver transplantation, to examine the microcirculation and early graft function after heterotopic auxiliary liver transplantation (HALT) with flow-regulated PVA, and to compare this technique with HALT with porto-portal anastomosis. Using the recently developed orthogonal polarization spectral (OPS) imaging, for the first time the microcirculation of liver grafts with PVA was visualized. MATERIALS AND METHODS: HALT was performed in Lewis rats. The portal vein was either completely arterialized via the right renal artery in a standardized splint-technique (Group I, n = 8) or anastomosed end-to-end to the recipient's portal vein (Group II, n = 8). RESULTS: After reperfusion, the average blood flow in the portal vein was within the normal range in Group I (1.7 +/- 0.4 ml/min/g liver weight) and significantly higher than in Group II (1.2 +/- 0.2 ml/min/g liver weight). The functional sinusoidal density in Group I (335 +/- 48/microm) was significantly higher than in Group II (232 +/- 58/microm), whereas the diameter of the sinusoids and the postsinusoidal venules yielded no significant differences between both groups. The bile production was comparable (27 +/- 8 versus 29 +/- 11 microl/h/g liver weight). CONCLUSIONS: In our experiments it was possible to achieve an adequate flow regulation in the arterialized portal vein with good results concerning microcirculation and early graft function. We recommend that further investigations on liver transplantation with PVA should be performed with portal flow regulation, before PVA is employed in clinical transplantation.     

Venous complications after orthotopic liver transplantation

Complications involving the portal vein or the vena cava, are rare after orthotopic liver transplantation. We report on the incidence and treatment of venous complications following 1000 orthotopic liver transplantations in 911 patients. Twenty-six of the adult patients (2.7%) suffered from portal complications after transplantation, whereas complications of the vena cava were observed in only 17 patients (1.8%). Technical problems or recurrence of the underlying disease (e.g. Budd-Chiari syndrome) accounted for the majority of complications of the vena cava, whereas alteration of the vessel wall or splenectomy during transplantation could be identified as important risk factors for portal vein complications. In patients undergoing modification of the standard end-to-end veno-venous anastomosis of the portal vein due to pathological changes of the vessel wall, complications occurred in 8.3%, whereas only 2.4% of patients who received a standard anastomosis of the portal vein experienced complications of the portal vein. Furthermore, splenectomy during transplantation was also associated with an increased incidence of portal vein complications (10.5 vs. 2.2% in patients without splenectomy). Treatment was dependent on the signs and symptoms of the patients, and varied considerably between patients with portal vein complications and patients suffering from complications of the vena cava. Complications of the vena cava led to retransplantation in about one-third of the patients, whereas in patients with occlusion of the portal vein, retransplantation was necessary in only 15%, and more than half of the patients suffering from portal vein complications did not require any treatment at all. Usually, treatment of patients with portal vein complications only became necessary when additional complications such as arterial occlusion or bile duct injuries occurred.     

Heterotopic segmental liver transplantation on splenic vessels after splenectomy with delayed native hepatectomy after graft regeneration: A new technique to enhance liver transplantation

We describe a patient with liver metastases from colorectal cancer treated with chemotherapy and hepatic resection, who developed unresectable multifocal liver recurrence and who received liver transplantation using a novel planned technique: heterotopic transplantation of segment 2-3 in the splenic fossa with splenectomy and delayed hepatectomy after regeneration of the transplanted graft. We transplanted a segmental liver graft after in-situ splitting without any impact on the waiting list, as it was previously rejected for pediatric and adult transplantation. The volume of the graft was insufficient to provide liver function to the recipient, so we performed this novel operation. The graft was anastomosed to the splenic vessels after splenectomy, and the native liver portal flow was modulated to enhance graft regeneration, leaving the native recipient liver intact. The volume of the graft doubled during the next 2 weeks and the native liver was removed. After 8 months, the patient lives with a functioning liver in the splenic fossa and without abdominal tumor recurrence. This is the first case reported of a segmental graft transplanted replacing the spleen and modulating the portal flow to favor graft growth, with delayed native hepatectomy.     

A new method for rat accessory hepatic transplantation — the cervical approach

Current methods for accessory liver transplantation in the rat require a high degree of microsurgical expertise and long training before success is achieved. We present a simpler method of arterialized accessory liver transplantation using the cervical vessels for revascularization of the transplanted liver with the cuff technique, which is useful for studies of liver preservation, reperfusion injury, and liver regeneration. After classical 70% hepatectomy is performed on the graft, the right common carotid artery is anastomosed to the donor aorta, the distal right external jugular vein is anastomosed to the donor portal vein, and the proximal right external jugular vein is anastomosed to the donor supradiaphragmatic inferior vena cava. The skin is not closed over the cervically transplanted liver (CTL). This method was used 30 times for periods of up to 6 h with a 90% success rate. CTL structure and function, as revealed by histology, bile flow rates, biliary bilirubin concentrating capacity, membrane potential, enzyme activity and distribution, have shown the CTL to be a structurally normal and metabolically active graft. In conclusion, the cervical approach to arterialized accessory liver transplantation is simple, and should prove useful for studies of liver preservation, reperfusion, regeneration, physiology, and toxicology.     

Intra-operative management of low portal vein flow in pediatric living donor liver transplantation

For pediatric living donor liver transplantation, portal vein complications cause significant morbidity and graft failure. Routine intra-operative Doppler ultrasound is performed after graft reperfusion to evaluate the flow of portal vein. This retrospective study reviewed 65 children who had undergone living donor liver transplantation. Seven patients were detected with suboptimal portal vein flow velocity following vascular reconstruction and abdominal closure. They underwent immediate on-table interventions to improve the portal vein flow. Both surgical and endovascular modalities were employed, namely, graft re-positioning, collateral shunt ligation, thrombectomy, revision of anastomosis, inferior mesenteric vein cannulation, and endovascular stenting. The ultrasonographic follow-up assessment for all seven patients demonstrated patent portal vein and satisfactory flow. We reviewed our experience on the different modalities and proposed an approach for our future intra-operative management to improve portal vein flow at the time of liver transplantation.     

Outcome of patients with pre-existing portal vein thrombosis undergoing arterialization of the portal vein during liver transplantation

Arterialization of the portal vein is being propagated as a technical possibility in liver transplant recipients with pre-existing portal vein thrombosis. In our own small series, portal vein arterialization (PVA) was carried out in four patients undergoing orthotopic liver transplantation. In three of these cases, the portal vein was anastomosed to the aorta via an interposed iliac artery, and in one case, directly to the hepatic artery. After PVA, all transplants showed regular initial function. Two patients died postoperatively after 19 and 50 days, of intra-abdominal haemorrhage and liver necrosis with thrombosis of the portal vein, respectively. A further patient had previously developed fibrosis of the liver, which led to the death of the patient 11 months after PVA. In the remaining patient, chronic rejection requiring re-transplantation developed 24 months after PVA had been performed. These unfavourable results prompt the conclusion that PVA cannot be recommended as a standard clinical procedure.     

Auxiliary partial orthotopic liver transplantation in the treatment of acute liver failure: a case report

A successful experience with auxiliary partial orthotopic liver transplantation (APOLT) for acute liver failure is reported in a 29-year-old woman who experienced jaundice, generalized erythema for 7 days, and decreased mentation for 3 days. Two months prior, she suffered pulmonary tuberculosis, being currently treated with antituberculous medications, which caused the fulminant hepatic failure. We decided to perform APOLT based on two facts. The first was the possibility that the diseased native liver may recover sufficiently to withdraw the immunosuppressants. Second, the pulmonary tuberculosis may have been worsened by immunosuppression. We removed the extended lateral section of the recipient for the graft. The left hepatic vein of the extended left lateral graft was anastomosed to the left hepatic vein of the recipient. The left portal vein of the graft was anastomosed to the left portal vein of the recipient. The right portal vein of the recipient was left without any manipulation. A duct-to-duct anastomosis was performed. On postoperative day 3, antituberculous medications were started. On the postoperative day 37, she was discharged without any problems. On the postoperative day 120, she showed no event of rejection, and her pulmonary symptoms improved. We performed the operation without transection of the portal branch to the native liver, but no functional competition has been discovered.     

A rare case of complex vascular reconstruction in liver transplantation.

Abnormalities of recipient or donor vascular structures are associated with reconstructive difficulties in liver transplantation. A patient with thrombosis of the right hepatic vein and associated stricture of the inferior vena cava (IVC), portal vein thrombosis and multiple aberrant arteries underwent orthotopic liver transplantation. The donor's suprahepatic IVC was anastomosed to the recipient's intrathoracic IVC. The portal vein flow was restored by venous graft interposition, while the arterial flow was ensured by interposing an iliac arterial graft anastomosed to the infrarenal aorta. In conclusion, graft function remains excellent more than 5 years postoperatively.     

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。     

Risk factors for intraoperative portal vein thrombosis in pediatric living donor liver transplantation

Pathologic changes of the recipient native portal venous system may cause thrombosis of the portal vein, especially in pediatric living donor liver transplantation (LDLT). This study assessed the utility of Doppler ultrasound (US) for the detection of intraoperative portal vein occlusion and identification of predisposing risk factors in the recipients. Seventy-three pediatric recipients who underwent LDLT at Chang Gung Memorial Hospital, Taiwan, from 1994 to 2002 were included. Preoperative and intraoperative Doppler US evaluation of the portal vein was performed. Age, body weight, native liver disease, type of graft, graft recipient weight ratio (GRWR), type of portal anastomosis, portal velocity, portal venous size and presence of portosystemic shunt were analyzed for statistical significance of predisposing risk factors. Eight episodes of intraoperative portal vein thrombosis, with typical findings of absent Doppler flow in portal vein and prominent hepatic artery with a resistant index lower than 0.5 (p < 0.001), were detected during transplantation, which was then corrected by thrombectomy and re-anastomosis. Children age < or =1 yr (p = 0.025), weight < or =10 kg (p = 0.024), low portal flow < or =7 cm/s (p = 0.021), portal venous size < or =4 mm (p = 0.001), and GRWR >3 (p < 0.017) were all risk factors for intraoperative portal vein thrombosis. Doppler US is essential in the preoperative evaluation, early detection and monitoring of outcome of the portal vein in liver transplant.     

Recanalized umbilico‐caval anastomosis as a temporary portosystemic shunt in pediatric living donor liver transplantation: the crossed fingers method

A temporary portocaval shunt (TPCS) associated with retrohepatic vena cava preservation prevents the edema caused by splanchnic congestion during liver transplantation (LT), especially for non‐cirrhotic cases. We herein report a modified TPCS technique using the recanalized umbilical vein and an end‐to‐side recanalized umbilico‐caval anastomosis for use during pediatric living donor liver transplantation (LDLT). This work evaluated a group of pediatric patients who underwent LDLT between 2001 and 2014 with the conventional TPCS (n=16) vs the recanalized umbilico‐caval shunt (the crossed fingers method, n=10). The crossed fingers method was performed by suturing an end‐to‐side anastomosis of the patent or recanalized umbilical vein to the vena cava using a continuous monofilament suture like “crossing the fingers,” that is, placing the left portal vein across the portal vein trunk next to it. The preoperative, surgical, and postoperative characteristics were similar in both groups except for the significantly shorter portal vein clamping time for the crossed fingers method. This method can allow the portal circulation to be totally decompressed before and after implanting the graft and while maintaining the hemodynamic stability throughout all stages of pediatric LDLT.     

Portal blood flow and liver regeneration in auxiliary partial orthotopic liver transplantation in a canine model

Functional competition has been shown to lead to a detrimental outcome in auxiliary liver transplantation. We evaluated the interaction in auxiliary partial orthotopic liver transplantation between the native liver and the graft in terms of portal flow and regeneration. The need for diversion of the portal flow to the graft was also assessed. Reduced-size liver grafts were transplanted orthotopically after partial hepatectomy in beagles. There were two groups: the preserved group, where portal inflow to the native liver was preserved, and the ligated group, where it was interrupted. Portal flow was measured serially and liver regeneration was evaluated on postoperative day 5. Functional competition was not observed in the preserved group. On the other hand, ligation of the native liver portal vein had no obviously detrimental effects on the remnant native liver. This leads to the conclusion that the portal vein to the native liver can be safely ligated to prevent functional competition.