Portal-to-right portal vein bypass for extrahepatic portal vein obstruction

Objective

Rex shunt (mesenteric-to-left portal vein bypass) is considered a more physiologically rational treatment for EHPVO than other portosystemic systemic shunts in children. However, about 13.6% of children with EHPVO do not have usable left portal veins and up to 28.1%. Rex operations in children are not successful. Hence, a Rex shunt in these children was impossible. This study reports a novel approach by portal-to-right portal vein bypass for treatment of children with failed Rex shunts.

Serial measurement of portal hemodynamics after partial portal decompression

In a serial analysis of splanchnic hemodynamics, we compared partial with total portal decompression in 16 alcoholic cirrhotic patients who underwent portacaval shunts for variceal hemorrhage. Partial decompression was achieved with 8 or 10 mm polytetrafluorethylene portacaval H grafts and aggressive collateral ligation. Total decompression was achieved with larger diameter H grafts (12 or 14 mm). Early and follow-up (mean interval, 18 months) postoperative studies of portal hemodynamics included: direct measurement of shunt gradients, scintigraphic quantitation of portal and mesenteric flow distribution to the liver, and a portal and splenic collateral scoring system developed from standardized splenic venography. Partial portal decompression reduced portal pressure by 43% +/- 8% compared with 81% +/- 5% after total decompression (p less than 0.01). Scintigraphy demonstrated that partial decompression provided a greater fraction of portal flow to the liver than did total decompression (57% +/- 9% versus 2% +/- 1% intrahepatic radioactivity) and mesenteric flow distribution (14.5% +/- 5.4% versus 1.2% +/- 0.7%). Only one patient with partial decompression had a significant loss of portal perfusion during the interval studies. Significantly more residual collaterals were visualized in patients with partial decompression than in those with total decompression, and interval studies showed no significant changes from early studies. We conclude that partial decompression maintains higher portal pressures, more residual collaterals, and a greater fraction of portal and mesenteric flow to the liver than does total decompression. A modest but uniform reduction of portal pressure minimizes stimulus for new collateral formation and further shunting of portal flow.     

CT门静脉成像的临床解剖学分析

目的 进行CT门静脉成像(computed tomography portal venography,CTPV)的临床解剖学分析,探讨其临床应用价值.方法 选取手术组(实验组)40例门静脉高压症合并上消化道出血患者和20例正常对照组进行CTPV临床读片与影像学测量,包括门静脉主干及其主要侧支血管.对胃左静脉的注入方式进行分类总结.应用直线拟合数学模型处理测量数据.结果 60例均成功进行CTPV摄片.实验组和对照组门静脉主干直径分别为(16.62±4.80) mm、(10.84±2.14) mm,肠系膜上静脉直径分别为(12.36±2.67) mm、(8.79±1.44) mm,脾静脉直径分别为(14.29±4.24) mm、(8.32±1.78) mm.实验组胃左静脉大部分注入脾-门交角和脾静脉.直线拟合11/18=X/30数学公式计算显示,阈值压力下门静脉主干X值=18.33 mm.胃左静脉食管支的显影率为52.38％、胃左静脉胃支显影率66.67％、胃左静脉食管支及胃支同时显影率23.81％,仍有相当一部分门脉高压患者胃左静脉的胃支和食管支显影不良甚至不显影.腹膜后静脉的显影率为25％.结论 应用CTPV在术前对食管胃底周围曲张的门静脉进行形态和功能的详尽评估,指导术者进行区域性断流(regional devascularization,RDV)具有实用价值及临床意义.CTPV显示胃左静脉注入脾-门交角和脾静脉的患者临床上出血的风险大.门静脉主干直径≥18 mm时可能出血,初步定义为CTPV阈值压力.CTPV在胃左静脉胃支/食管支的精细结构显示上仍然具有一定的局限性.CTPV中提高腹膜后静脉显影率应予关注.     

搏动性门静脉血泵治疗门静脉高压症的实验研究

目的　为解决门静脉高压症向肝血流减少、肝代谢功能下降及侧支循环压力过高、静脉曲张等问题 ,我们研制了搏动性门静脉血泵 ,对丝线栓塞性门静脉高压模型犬进行门静脉外动力泵血的研究。观察入肝血量、肝代谢变化及侧支压力等一系列指标。方法　对杂种犬进行门静脉左右支丝线栓塞术制备门静脉高压动物模型 ;应用高弹力硅胶球囊连接单流向硅胶瓣“T”型管 ,制作搏动性门静脉血泵 ;应用强磁场磁极片及低频振荡交流线圈体外提供动力。将血泵“T”管安置于门静脉主干前壁侧支平面以上 ,测定血泵工作前后的入肝血流量、侧支静脉压力及吲哚氰绿排泄的变化。结果　模型犬血泵平面以上的门静脉压力在泵工作后由 30 3± 4 2cmH2 O升至 49 0± 7 1cmH2 O ;入肝血流量由 2 70± 2 8ml/min升至 396± 2 5ml/min ;血泵平面以下门静脉压由 31 4± 3 1cmH2 O降至18 0± 4 3cmH2 O ;脾静脉压由 36 2± 4 0cmH2 O降至 2 0 5± 3 4cmH2 O ;胃底静脉压由 35 3± 3 3cmH2 O降至 19 3± 4 7cmH2 O ;吲哚氰绿排泄率由 0 0 92± 0 0 0 9升至 0 15 1± 0 0 13 ;15min滞留率由 19 0 3± 8 5 0降至 9 0 4± 2 5 0。结论　搏动性门静脉血泵对增加门静脉入肝血流 ,改善肝代谢功能状态及降低侧支压力具有显著作用。血泵结构     

Preduodenal portal vein

Passage of the portal vein anterior to the duodenum is a rare vascular anomaly that is a result of a variation in the normal developmental pattern of the right and left vitelline veins and their three anastomotic channels. In operations on the duodenum or biliary tract in patients with this condition, there is marked danger of inadvertent tearing, division, ligation, or excessive handling causing thrombosis. One case is added to the twenty-five previously reported in the literature.     

Bilharzial portal fibrosis: an important cause of portal hypertension

Thirty consecutive cases of portal hypertension seen in a surgical unit in Lusaka, Zambia, are reported. Of these cases 70% were due to portal fibrosis caused by Schistosoma mansoni infestation. Portacaval shunting was undertaken in most cases. Patients with portal fibrosis responded more favourably to portal decompression than did patients with cirrhosis. It is probable that the condition is more common than is generally reconigzed in areas where S. mansoni infestation is endemic.     

Endoscopic ultrasound-guided portal pressure gradient measurement in managing portal hypertension

Portal hypertension (PH) is still a challenging clinical condition due to its silent manifestations in the early stage and needs to be measured accurately for early detection. Hepatic vein pressure gradient measurement has been considered as the gold standard measurement for PH; however, it needs special skill, experience, and high expertise. Recently, there has been an innovative development in using endoscopic ultrasound (EUS) for the diagnosis and management of liver diseases, including portal pressure measurement, which is commonly known as EUS-guided portal pressure gradient (EUS-PPG) measurement. EUS-PPG measurement can be performed concomitantly with EUS evaluation for deep esophageal varices, EUS-guided liver biopsy, and EUS-guided cyanoacrylate injection. However, there are still major issues, such as different etiologies of liver disease, procedural training, expertise, availability, and cost-effectiveness in several situations with regard to the standard management.     

Mesenterico left portal bypass for variceal bleeding owing to extrahepatic portal hypertension caused by portal vein thrombosis

Background/Purpose

Portosystemic shunt operations are indicated in patients with extrahepatic portal hypertension owing to portal vein thrombosis (EPH-PVT) suffering from recurrent variceal bleeding despite endoscopic sclerotherapy. Mesenterico left portal bypass procedure (MLPB) is an alternative procedure to the portosystemic shunt operations in patients with EPH-PVT. MLPB operation reestablishes hepatopetal portal blood flow. We herein present our experience with MLPB in children with EPH-PVT.

Methods

Six patients were treated for EPH-PVT with recurrent bleeding despite endoscopic sclerotherapy (2 boys and 4 girls) in our unit. All patients were evaluated preoperatively with complete blood count, portal duplex system Doppler ultrasonography, magnetic resonance angiography, and upper gastrointestinal (GI) endoscopy. MLPB operation was performed as described by de Ville de Goyet. During the postoperative period, patients were evaluated with complete blood count, portal duplex system Doppler ultrasonography, upper GI endoscopy, and magnetic resonance angiography.

Results

Six patients were assessed to be candidates for MLPB procedure and were operated to perform the MLPB procedure. Left portal veins were found to be patent during the operation in 4 patients, and the MLPB procedure was performed. Internal jugular vein was used in 3 patients and enlarged inferior mesenteric vein in 1 patient. Left portal veins of the remaining 2 patients were found to be obliterated; therefore, mesocaval shunt was performed. The postoperative course of the patients was uneventful except for 1 patient. During the following period, the leukocyte and the platelet counts were significantly increased in 3 of the 4 patients after the MLPB procedure. Upper GI bleeding occurred in the early postoperative period in 1 patient with MLPB procedure because of prepyloric ulcer that was successfully treated by endoscopic sclerotherapy. Internal jugular vein graft thrombosis was detected on the 10th postoperative day. This patient underwent a second laparotomy, the distal half of the graft was found to be sclerosed and narrowed that the graft was revised with a synthetic allograft.

Conclusions

Based on a review of the literature, the MLPB functions well in patients with portal hypertension caused by portal vein thrombosis and appears to have a physiologic advance over shunts that decompress but do not return blood directly to the liver. Because intra-abdominal veins appear to function well as a conduit in this operation, it may be favored by eliminating additional incision and increased risk in such patients.     

Bilharzial portal hypertension

Schistosomiasis is a major world health problem that is being encountered more frequently in North America as the immigration patterns from endemic areas change. At Henry Ford Hospital in Detroit, only two admissions for active schistosomiasis were recorded before 1970, but since then there have been 43 such cases. Of these 45 patients, six required seven portasystemic shunts, primarily to treat the complication of esophageal variceal hemorrhage, which is associated with portal hypertension secondary to presinusoidal hepatic fibrosis. No operative deaths occurred, and follow-up averaging 6.6 years revealed no late deaths and minimal encephalopathy. These excellent results are attributed to successful portal decompression and the well-preserved liver function that is typical of these patients. Bilharzial portal hypertension should be suspected in immigrants from endemic areas who have bleeding esophageal varices.     

区域性门脉高压

区域性门脉高压症（Regional Portal Hypertension,RPH）,亦有称为“左侧门脉高压”、“局限性门脉高压”等。占肝外型门脉高压症的5％,但却是唯一可治愈的门脉高压症。常为多种原因引起的单纯性脾静脉梗阻,致门静脉脾胃区压力增高超过正常。它除了可引起脾脏淤血肿大外,还可形成孤立性胃底静脉曲张;而门静脉、肠系膜静脉及食道静脉则较少受影响。     

Idiopathic portal hypertension

The authors present a report of 14 patients with the syndrome of portal hypertension without liver cirrhosis and with recurring esophagogastric bleedings. The cause of the alterations in portal hemodynamics remains unknown. Operative treatments (splenorenal shunts in 9 cases, 3 splenectomies and 1 ligation of the splenic artery) were successful. Two patients in whom splenectomy had been performed in combination with omentohepatopexy died 6 and 10 years after operation due to recurrent hemorrhages. The other patients did not have recurrent bleedings, but in 6 patients 6-10 years after splenorenal shunts there appeared other diseases (encephalopathy, nephrolithiasis, arterial hypertension, duodenal ulcer). The authors consider that indications for shunting operations for idiopathic portal hypertension, especially when using renal veins, should be determined more carefully, phlebosclerotic therapy and transsection of the esophagus being recommended as alternative interventions.