Arterialization of the portal vein in pediatric liver transplantation

Portal vein arterialization (PVA) is an acquired concept in shunt surgery for portal hypertension. This technique, recently described as both a temporary and permanent procedure in adult liver transplantation, is reported by the authors in two cases of pediatric transplantation. The indication was low portal blood flow after reperfusion with poor graft function due to persistence of spontaneous retroperitoneal venous shunts. In both cases described, PVA allowed for satisfactory macroscopic liver reperfusion. The increase in portal blood flow from 150 to 500 ml/min in the second patient enabled the liver to be reperfused correctly and led to successful transplantation. The graft function in both cases improved in the 1st postoperative week, but thrombosis of the PVA occurred in the 1st patient 2 months after transplantation. Signs of hepatic hyperarterialization occurred in the second patient and this necessitated a dearterialization of the portal vein 2 weeks later. Although the benefit of this procedure appears to be beyond doubt in the immediate postoperative period, we have no data on long-term arterialization. We do think that PVA can be performed in pediatric liver transplantation, but it may need to be done only in special, individual situations when no valid alternative can be proposed, such as in the absence of a mesenteric vein and/or the presence of spontaneous retroperitoneal venous shunts. Received: 24 June 1997 Received after revision: 27 November 1997 Accepted: 28 November 1997     

Reconstruction of portal vein using a hepatic vein patch graft after combined hepatectomy and portal vein resection

BACKGROUND: Surgical resection is the only treatment modality that ensures complete tumor removal in patients with liver tumors involving a major portal vein branch or its bifurcation. Restoration of good portal blood flow is essential for recovery in the early postoperative period and for long-term survival. However, such extended resections often result in large defects at the bifurcation of the portal vein that are not amenable to suturing or end-to-end anastomosis. METHODS: A patch graft technique is very useful for reconstruction of long and elongated defects when other methods are not technically appropriate. We describe a simple technique for reconstructing the portal vein using a patch graft obtained from the hepatic vein stump of the resected specimen. CONCLUSIONS: This technique permits surgeons to reconstruct the portal vein without any need for harvesting another vein and with no need for an additional incision.     

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     

改进的门静脉套管置人技术在大鼠肝移植中的应用

目的 探讨改进的门静脉套管置入技术“门脉分支悬吊法”在大鼠肝移植门静脉重建中的应用效果.方法 “双袖套法”建立大鼠肝移植模型,分别应用改进的“门脉分支悬吊法”和传统方法行受体门静脉重建,比较门静脉重建所需时间和成功率、无肝期时间以及移植手术成功率.结果 应用改进的“门脉分支悬吊法”行大鼠肝移植(n=35),受体门静脉重建成功率94.3％,门静脉吻合所需时间仅为(1.9±0.7)min,无肝期为(21.8±2.2)min,移植手术成功率为80％,优于传统方法(P＜0.05).术后l周存活率为85.8％,与传统方法比较无统计学差异(P＞0.05).结论 改进的“门脉分支悬吊法”缩短了受体门静脉吻合时间和无肝期,提高了门静脉重建成功率和移植手术成功率,可以快速、安全地实现大鼠肝移植受体手术中的门脉套管置入和门静脉重建.     

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.     

Hepatic artery interruption followed by portal vein thrombosis in an adult liver transplant

Vascular complications following liver transplantation result in significant morbidity and mortality. We report a 28-year-old man who, because of a mycotic false aneurysm, underwent ligation of the hepatic artery 4.5 weeks post-transplantation and who, 4.5 months later, suffered a portal-mesenteric vein thrombosis. Adverse hepatic sequelae did not follow these events, demonstrating the capacity of the collateral circulation to perfuse the transplanted liver.     

Arguments for a selective approach of preoperative portal vein embolization before major hepatic resection

Preoperative PVE can induce hypertrophy of the future liver remnant volume resulting in a decrease of surgical risk after major hepatic resection. However, the number of patients with normal liver at risk is small and there is no arguments for inducing hypertrophy before standard right hepatectomy. Therefore, in patients with normal liver PVE is indicated in patients in whom very extended liver resection or associated major gastro-intestinal surgery is planned. In patients with chronic liver disease and in those with injuried liver (chemotherapy, major steatosis, cholestasis), PVE is indicated before major liver resection.     

Hemodynamic interaction between portal vein and hepatic artery flow in small-for-size split liver transplantation

In split-liver transplantation, the entire portal flow is redirected through relatively small-for-size grafts. It has been postulated that excessive portal blood flow leads to graft injury. In order to elucidate the mechanisms of this injury, we studied the hemodynamic interactions between portal vein- and hepatic artery flow in an experimental model in pigs. Six whole pig liver grafts were implanted in Group 1 ( n=6) and six whole liver grafts were split into right and left grafts and transplanted to Groups 2 ( n=6) and 3 ( n=6), respectively. The graft-to-recipient liver volume ratio was 1:1, 2:3 and 1:3 in Groups 1, 2 and 3, respectively. Portal vein- and hepatic artery flows were measured with an ultrasonic flow meter at 60,120 and 180 min after graft reperfusion. Portal vein pressure was also recorded at the same time intervals. Graft function was assessed at 3,6h and 12h, and morphological changes at 12h after reperfusion. Following reperfusion, portal vein flow showed an inverse relationship to graft size, while hepatic artery flow was reduced proportionately to graft size. The difference was significant among the three groups ( P<0.05). Portal vein pressure was significantly higher in group 3, compared to groups 1 and 2 ( P<0.05). Hepatic artery buffer response was significantly higher in Group 3, compared to Groups 1 and 2 in relation to pre-occlusion values ( P<0.05). Split-liver transplantation, when resulting in small-for-size grafts, is associated with portal hypertension, diminished arterial flow, and graft dysfunction. Arterial flow impairment appears to be related to increased portal vein flow.     

缝扎肝右静脉后肝动脉与门静脉血流改变的实验研究

目的：探讨结扎主肝静脉对肝动脉与门静脉血流动力学的影响。方法：小型猪共12头，剖腹后，电磁血流计测量结扎前后肝动脉、门静脉血流，大网膜静脉置管测量结扎前及结扎后30min、1、3、5、7、14、21、28、56d的自由门静脉压力(FPP)，56d后再次开腹测量肝动脉、门静脉血流。结果：FPP术后均升高，以术后7d内明显，6头超过35cmH2O，且其中3头小猪出现上消化道出血；肝动脉血流速早期增加，56d降至略高于术前水平；门静脉血流速早期减少，未检测到逆向血流，术后56d，门静脉血流速恢复为略低于术前水平。结论：结扎一条主肝静脉不会引起结扎肝叶的萎缩坏死，可能会导致上消化道出血。     

门静脉和肝动脉结扎序贯二步法肝切除术治疗巨大肝癌

巨大肝癌切除术后剩余肝脏体积不足是发生肝衰竭的主要原因.通过阻断一侧的门静脉和肝动脉,使肿瘤降低分期,增加对侧术后剩余肝脏体积,成为目前切除巨大肝癌的方法之一.2013年3-4月厦门大学附属第一医院收治的1例原发性右半肝巨大肝癌患者,因肝脏剩余体积不足,术者一期行选择性门静脉及肝动脉结扎术后,序贯二期行肝切除术.患者2次手术均顺利完成,一期行门静脉右支及肝右动脉结扎术,术后肝肿瘤体积缩小,剩余左半肝代偿性增生良好,肝脏体积由术前488 mL增加到术后1个月689 mL.一期手术后33 d顺利实施二期巨大肝癌肝切除术,2次术后均无严重并发症发生.术后随访2个月,患者剩余肝脏未见肿瘤复发,AFP由术前425 mg/L降至26×10^-3mg/L.因此,选择性门静脉及肝动脉结扎后序贯二步法肝切除术可能是传统手术无法切除的巨大肝癌患者有效的治疗方法.     

Use of autogenous saphenous vein as a conduit for mesenterico-left portal vein bypass

The authors describe a case of extrahepatic portal vein (EHPV) thrombosis and portal hypertension treated with a variant of mesenterico-left portal vein bypass (MLPVB) or Rex shunt. In this case, a segment of autogenous greater saphenous vein was used to bridge the distance between the left gastric vein inflow and the left portal vein. Use of such nontraditional conduit in similar circumstances may expand the application of portal revascularization/decompression procedures in treating these patients.     

Reconstructing the portal vein through a posterior pancreatic tunnel: New choice for portal vein thrombosis during liver transplantation

BACKGROUNDThrombectomy and anatomical anastomosis (TAA) has long been considered the optimal approach to portal vein thrombosis (PVT) in liver transplantation (LT). However, TAA and the current approach for non-physiological portal reconstructions are associated with a higher rate of complications and mortality in some cases.AIMTo describe a new choice for reconstructing the portal vein through a posterior pancreatic tunnel (RPVPPT) to address cases of unresectable PVT.METHODSBetween August 2019 and August 2021, 245 adult LTs were performed. Forty-five (18.4%) patients were confirmed to have PVT before surgery, among which seven underwent PV reconstruction via the RPVPPT approach. We retrospectively analyzed the surgical procedure and postoperative complications of these seven recipients that underwent PV reconstruction due to PVT.RESULTSDuring the procedure, PVT was found in all the seven cases with significant adhesion to the vascular wall and could not be dissected. The portal vein proximal to the superior mesenteric vein was damaged in one case when attempting thrombolectomy, resulting in massive bleeding. LT was successfully performed in all patients with a mean duration of 585 min (range 491-756 min) and mean intraoperative blood loss of 800 mL (range 500-3000 mL). Postoperative complications consisted of chylous leakage (n = 3), insufficient portal venous flow to the graft (n = 1), intra-abdominal hemorrhage (n = 1), pulmonary infection (n = 1), and perioperative death (n = 1). The remaining six patients survived at 12-17 mo follow-up.CONCLUSIONThe RPVPPT technique might be a safe and effective surgical procedure during LT for complex PVT. However, follow-up studies with large samples are still warranted due to the relatively small number of cases.     

合并门静脉血栓形成患者的肝移植21例

目的探讨肝移植术中门静脉血栓的处理方法，评价移植术前门静脉血栓形成对肝移植疗效的影响。方法回顾性分析267例270次肝移植的临床资料。267例受者中，术中明确存在门静脉血栓者21例，占7．8％，其中12例术前通过彩色多普勒超声、计算机断层扫描血管造影或磁共振成像明确诊断。按照Yerdel门静脉血栓分级法，1级8例，2级5例，3级6例，4级2例。肝移植术中根据门静脉血栓分级的不同，采取相应处理方式：1级和2级者选择单纯血栓切除或血栓累及段门静脉切除，然后将供、受者的相应血管行端端吻合；3级和4级者采取供者肠系膜上静脉或髂静脉在供肝门静脉与受者肠系膜上静脉或门静脉系统属支间架桥等方式重建供肝门静脉循环。结果21例术前存在门静脉血栓形成的患者均顺利完成肝移植手术。4例Yerdel分级为3级的受者术后早期（8～21d）死亡，死亡率为19．0％，显著高于术前无门静脉血栓者（8．5％，P（0．01）。21例受者中，1例术后3个月时再次发生门静脉血栓形成，再次血栓形成发生率为4，8％，显著高于术前无门静脉血栓形成者（0．8％，P〈0.01）。17例术前存在门静脉血栓形成的患者肝移植后康复出院，其1年存活率为94．1％，与术前无门静脉血栓形成的良性肝病受者（93.8％）比较，差异无统计学意义（P〉0．05）。结论术前存在的门静脉血栓形成并非肝移植的绝对禁忌证，术中根据门静脉血栓分级选择适宜的手术处理方式可顺利完成肝移植手术，并取得与无门静脉血栓形成者相近的远期疗效。     

门静脉主干缩窄法制备SD大鼠门静脉高压症模型时最佳口径的探讨

目的 探讨缩窄门静脉主干法制备SD大鼠门静脉高压症模型时的最佳缩窄口径.方法 SD大鼠70只,随机分为正常组和6个实验组,每组各10只.正常组行假手术.各实验组分别按照5、6、7、8、9、12号针头的缩窄口径行门静脉主干缩窄术.观察各组大鼠术后累积死亡率,术后状态,术前、术后即刻及术后2周时的门静脉压力,术后2周时的食管组织学变化和脾指数.结果 5、6、7、8、9、12号针头缩窄组术后3 d时大鼠的累积死亡率分别为100%、80%、70%、20%、10%、0%,与缩窄程度正相关.8、9、12号组的大鼠存活状态明显好于5、6、7号组.5、6、7、8、9、12号组术后即刻门静脉压力分别为:(5.836±0.275)、(4.557±0.419)、(3.856±0.576)、(3.343±0.433)、(2.708±0.309)、(1.957±0.358)kPa,7、8、9、12号组术后2周时门静脉压力分别为:(2.163±0.424)、(1.956±0.172)、(1.841±0.202)、(1.232±0.154)kPa,均较正常(0.881±0.165)kPa显著升高(P＜0.05).术后2周,7、8、9、12号组大鼠食管下段黏膜下层平均血管数目分别为:(3.94±0.83)、(3.58±0.63)、(3.14±0.64)、(2.02±0.62)个,与正常组(1.65±0.62)个比较,除12号组外均有增多(P＜0.01);固有层平均血管数目分别为:(2.24±0.64)、(2.05±0.29)、(1.52±0.28)、(0.93±0.19)个,与正常组(0.82±0.18)比较,除第12组外均增多(P＜0.01);黏膜下层血管口径分别为:(4.52±1.51)、(4.05±1.23)、(3.75±1.11)、(2.03±0.86)μm,除第12组外均增大(P＜0.01);脾指数分别为:(4.21±0.93)、(4.06±0.68)、(3.84 4±0.71)、(3.31±0.69)除12号组外也较正常增加(P＜0.01).结论 缩窄门静脉主干可成功制成大鼠门静脉高压症模型;其最佳缩窄口径应该是:大鼠体重200 g左右时用8号针头(直径0.8mm),大鼠体重300 g左右时用9号针头(直径0.9 mm).     

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.     

Decrease in hepatic circulation induces hepatic fibrosis in a neonatal piglet model with short bowel syndrome

Background

Regarding the complications associated with short bowel syndrome (SBS), progressive liver failure is one of the most severe complications known to occur: Although several studies have suggested that many factors interactively influence this clinical condition we investigated the relationship between hepatic circulation and hepatic fibrosis using a neonatal piglet SBS model.

Materials and Methods

This study used the following 4 groups of neonatal piglets: a group with an 80% resection of the small bowel (SBS group), a group with a bypass operation of the small bowel (functional SBS group), a group with only a laparotomy as a sham operation (sham group), and a no operative treatment group (control group). We measured the hepatic circulation just before and after the reconstruction of the intestine, as well as on the 7th and 14th postoperative day. In addition, both blood and hepatic tissue samples were collected to investigate them both biochemically and morphologically.

Results

Regarding the biochemical liver function and the tissue blood flow of liver, there were no significant differences among all groups on any investigated days. However, on both the 7th and 14th postoperative days, the portal venous flow in the SBS group was significantly lower than that in other groups. According to a histological analysis, only hepatic samples on the 14th postoperative day showed mild hepatic fibrosis in the SBS group. Regarding the α-smooth muscle actin staining findings that expresses active stellate cells, numerous positive cells were found to be distributed in the perisinusoidal space on the 14th postoperative day in the SBS group.

Conclusion

Based on our data, a decrease in the hepatic circulation, especially in the portal venous flow, after a massive resection of the intestine may cause progressive liver dysfunction because of the activation of hepatic stellate cells.     

肝移植术后门静脉并发症的诊断和治疗(附6例分析)

目的 探讨肝移植术后门静脉并发症的诊断和治疗。方法 回顾性分析160例原位肝移植临床资料。结果 肝移植术后门静脉并发症发生率为3．75％,与门静脉并发症相关死亡率为0。门静脉狭窄发生率为1．25％,门静脉栓塞发生率为2．5％,需治疗的门静脉并发症占33．3％。结论 术前有门脉高压症手术治疗史、移植术前门静脉血栓、门静脉手术史以及严重感染病史等是门静脉并发症的高危因素;彩色多普勒超声检查是监测门静脉并发症的有效方法,确诊门静脉并发症依赖门静脉造影;有症状的门静脉并发症需及时行再血管化手术。     

门静脉动脉化对大鼠肝脏再生的影响

目的探讨门静脉动脉化重建肝血流后对肝脏再生的影响。方法建立门静脉动脉化重建肝脏血流加半肝切除(43%)的大鼠实验模型,分别在术后3 d和10 d取出肝脏烘干称重、光镜下计数进入有丝分裂期的肝细胞和分离肝细胞进行流式细胞仪分析,以观察肝脏再生的情况。结果实验组术后3 d和10 d测定的肝脏干重分别为(67.56±3.70)%(、78.76±5.68)%,与对照组(71.66±3.24)%(、82.38±4.86)%相比无显著性差异(P>0.05);进入有丝分裂期的肝细胞计数(708.4±68.21、239.6±24.50)与对照组(724.8±69.99、216.2±23.81)相比无显著性差异(P>0.05);流式细胞仪测得的进入G2和M期的肝细胞的DNA含量[(25.72±4.78)%、(15.60±2.52)%]与对照组[(28.78±3.37)%、(13.34±2.88)%]相比无显著性差异(P>0.05)。结论行门静脉动脉化重建肝血流不影响肝脏的再生。