Adjacent Portal Vein Research Articles

The methodology for endoluminal irreversible electroporation in porcine models

The aim of this study was to describe the methodology of the surgical technique for endoluminal irreversible electroporation in the biliary tract performed within the perihilar region in porcine models. Endoluminal irreversible electroporation of the common bile duct was performed on eight porcine models using an endoluminal device inserted during laparotomy. The endoluminal device consisted of three electrodes 1 cm in length, attached at 120 degrees around the balloon catheter. The procedure was conducted with the following parameters: number of pulses 90, voltage of 1500 V between each couple of electrodes. Cross sectional imaging and histopathological assessment were employed for evaluations of the ablation zone. Models were sacrificed 24 h and 96 h after ablation. The treatment was successful in all porcine models. All animals survived the defined study period. Peri-ablation oedema within the hepatoduodenal ligament and adjacent liver tissue could be measured on post-procedural MRI or CT. Perforation in the site of ablation developed in one model. Histopathological examination showed heavy regressive changes of the ablated tissue. The elastic membranes of the adjacent portal vein were preserved in all models. In our experience, this novel endoluminal modality used within the perihilar region in porcine models is a feasible and well predictable procedure. Further studies should explore the optimal protocol of catheter-based ablation to limit complications.

Combined Portal Vein Resection for Hilar Cholangiocarcinoma: A Meta-analysis of Comparative Studies

Hilar cholangiocarcinoma (HCCA) frequently invades into the adjacent portal vein, and portal vein resection (PVR) is the only way to manage this condition and achieve negative resection margins. However, the safety and effectiveness of PVR is controversial. Studies analyzing the effect of PVR on the surgical and pathological outcomes in the management of HCCA with gross portal vein involvement were considered eligible for this meta-analysis. The outcome variables analyzed included postoperative morbidity, mortality, survival rate, proportion of R0 resection, lymph node metastasis, microscopic vascular invasion, and perineural invasion. From 11 studies, 371 patients who received PVR and 1,029 who did not were identified and analyzed. Data from patients who received combined PVR correlated with higher postoperative death rates (OR = 2.31; 95 % CI, 1.21–4.43; P = 0.01) and more advanced tumor stage. No significant difference was detected in terms of morbidity, proportion of R0 resection, or 5-year survival rate. Subgroup analysis demonstrated that in centers with more experience or studies published after 2007, combined PVR did not cause significantly higher postoperative death. No strong evidence could suggest that combined PVR leads to more morbidity or mortality for patients with HCCA when the portal vein is grossly involved. In addition, combined PVR is oncologically valuable because R0 resection and 5-year survival did not differ significantly between two cohorts, despite the fact that the PVR cohort consisted of patients with more advanced HCCA.

Abstract No. 412 - CT spectrum of findings in liver parenchyma after transarterial chemoembolization with DC-beads

Purpose To describe MDCT findings and parenchymal changes after transarterial chemoembolization (TACE) with DC-beads in the treatment of primary and metastasic liver tumors. Materials and Methods Baseline and follow-up CT scans obtained in 93 patients with TACE DC-bead treatment between September 2009 and March 2012 were reviewed retrospectively to evaluate changes in biliary ducts, adjacent portal vein branches and hepatic parenchyma. Clinical data including etiology and correlation with CT findings were analyzed using the Fischer test. A p Results 93 patients, 55 men and 38 women (21-78 years) were evaluated. Etiologies included 44 hepatocellular carcinomas (38 with cirrhosis), 17 neuroendocrine metastases, 10 colorectal metastases and 22 others. The average time between TACE and follow-up CT was 50 days (r6-172). The most frequent findings at follow-up were bile duct dilatation (41.9%, n 39), obliteration of adjacent intrahepatic portal vein branches (31.1%, n 29), bilomas (26.8%, n 25), parenchymal hypodense ill-defined areas (44%, n 41), parenchymal infarcts (6.4%, n 6), periportal edema (35.4%, n 33) and perilesional parenchymal enhancement (23.6%, n 22). One patient (1.07%) had an abscess. The first 4 findings showed significant negative association with cirrhosis. In spite of these findings, there were no clinical relevant manifestations in these patients. There were no mayor complications reported. Only one patient required a percutaneous drainage catheter to drain an abscess. Conclusion The spectrum of MDCT findings we report after transarterial chemoembolization with DC-beads were not related with clinical manifestations of mayor complications in most cases. It is important for the radiologist to be familiar with these changes in order to distinguish collateral findings from complications and residual or recurrent tumor.

Palliation of jaundice in pancreatic cancer: stent or surgery?

Pancreatic cancer still remains a lethal disease, and a large proportion of patients present for treatment at an advanced stage. Surgical resection is still the best hope for cure, but is only possible in localized disease. Locally advanced tumors may benefit from en bloc resection of the superior mesenteric vein or adjacent portal vein, and neoadjuvant chemoradiation may help to render some advanced tumors resectable. For the majority of other locally advanced or disseminated pancreatic head cancers, palliation is the only realistic option. Patients may suffer from obstructive jaundice, with or without cholangitis, and disabling pruritus, from vomiting due to obstruction to the gastric outlet, and other symptoms such as anorexia or abdominal pain. What is the optimal approach to palliating patients with obstructive jaundice due to pancreatic cancer? Patients may be classified into two groups: those with obviously unresectable or metastatic disease on preoperative evaluation or with severe comorbid illness which precludes operation or renders it at high risk; and those where preoperative imaging indicates a possibly resectable pancreatic tumor. In patients where evaluation has established that the tumors or patients are unsuitable for surgical resection, the decision to employ nonsurgical palliation is more straightforward. Expandable metallic stent insertion provides effective palliation of jaundice, duodenal stents may be used for gastric outlet obstruction (although these may be difficult to place when the obstruction extends to the third part of the duodenum), and endoscopic ultrasound-guided or percutaneous celiac plexus neurolysis may be employed for relief of intractable pain. In this issue of the Journal, Nikfarjam et al. [1] have compared the outcomes following stent insertion vs. surgical bypass. The “majority” of their patients who underwent surgical bypass were candidates for curative resection which were found to be unresectable on the operation table. Stents were used in older patients and those with poor performance status and deeper jaundice. Overall, survival figures were comparable, though stent insertion was followed by a significantly larger number of reinterventions, and 13 % required subsequent surgical intervention. Forty-one percent of metallic stents blocked over a median follow up of 224 days. The paper highlights a number of interesting observations: (a) patients who underwent stenting were less likely to undergo palliative chemotherapy—presumably their general condition was too poor to allow the use of chemotherapy; (b) the majority of stent blockage could be treated by restenting, and the chief area of failure was the development of duodenal obstruction; and (c) the only factor affecting survival was the presence of metastatic disease. Patients without meta

Ischemic liver injuries after hepatic artery embolization in patients with delayed postoperative hemorrhage following hepatobiliary pancreatic surgery

Many collateral pathways to the liver are dissected during hepatobiliary pancreatic surgery and, if the arterial bleeding is massive and a hematoma becomes larger, the adjacent portal vein can be compressed with impairment of the portal venous flow. To evaluate the frequency and severity of ischemic liver injuries after hepatic artery embolization in patients with delayed postoperative arterial hemorrhage after hepatobiliary pancreatic surgery. Eighteen patients undergoing proper or common hepatic artery embolization for delayed postoperative arterial hemorrhage after hepatobiliary pancreatic surgery achieved hemostasis. To evaluate the frequency and severity of ischemic liver injuries, the liver enzyme levels and CT findings before and after hepatic artery embolization were retrospectively compared and the clinical outcomes after hepatic artery embolization were analyzed. Angiographic findings were also analyzed to reveal any association with development of ischemic liver injuries after hepatic artery embolization. Ischemic liver injuries were observed in 15 (83%) of 18 patients undergoing hepatic artery embolization for postoperative hemorrhage. Injuries included hepatic infarction combined with abscess in one (5%) patient, hepatic infarction in 12 (67%) patients, and transient hepatic ischemia/dysfunction in two (11%). As for the extent of hepatic infarction, lobar infarction developed in two patients and subsegmental infarction in 11. One patient with right hepatic lobar infarction died of hepatic failure 11 days after hepatic artery embolization. In the other 14 patients with ischemic liver injuries, the elevated liver enzymes returned to baseline levels within two weeks. All of the four patients with portal vein stenosis, four patients with no hepatic arterial flow on post-embolization angiogram, and one patient with both had hepatic infarction after hepatic artery embolization. No ischemic liver injuries developed after hepatic artery embolization in three patients with no portal vein stenosis and bilobar hepatic arterial flow via the left hepatic artery aberrantly arising from the left gastric artery or from the common hepatic artery. Ischemic liver injuries can develop in most patients undergoing hepatic artery embolization for postoperative arterial hemorrhage after hepatobiliary pancreatic surgery; hepatic infarction appears to be the most frequent type of ischemic liver injury. Hepatic artery embolization for postoperative arterial hemorrhage after hepatobiliary pancreatic surgery may carry a great risk of ischemic liver injury if a patient has portal vein stenosis or no aberrant hepatic artery.

Bile duct injuries leading to portal vein obliteration after transcatheter arterial chemoembolization in the liver: CT findings and initial observations.

To document the computed tomographic (CT) findings of transcatheter arterial chemoembolization (TACE)-induced, localized bile duct injuries leading to portal vein branch obliteration in the liver and to elucidate the clinical implications with retrospective review of the authors' experiences. Follow-up CT scans obtained in 11 patients with TACE-induced intrahepatic bile duct dilatation were reviewed retrospectively to evaluate serial changes in the adjacent portal vein branches and hepatic parenchyma. Clinical data, including time between TACE and CT and serum alkaline phosphatase levels, also were analyzed. Of 11 patients with marked (n = 8) or mild (n = 3), lobar (n = 4) or segmental (n = 7) bile duct dilatation with or without bile collection in the tissue sheaths of the Glisson capsule or hepatic parenchyma, nine (82%) had bile duct changes at the first CT follow-up, within 1 month after TACE. Marked narrowing or obliteration of the adjacent intrahepatic portal vein branches in 10 (91%) patients resulted in progressive atrophy of the corresponding hepatic parenchyma in nine (82%) at variable times after TACE. The serum alkaline phosphatase level increased to more than 200 U/L in eight (89%) of nine patients 1 month after TACE. TACE-induced intrahepatic bile duct injury resulting in obliteration of the adjacent portal vein branch seems to be one cause of hepatic parenchymal atrophic changes after TACE.

Treatment strategies for hepatic metastasis from colorectal cancer

Hepatic micrometastases of the parenchyma adjacent to a macroscopic lesion were detected in 17 of 31 resected liver metastases. Fifty-nine micrometastatic lesions were detected in total; 26 lesions were situated in the portal vein (PV), 22 in the central vein (CV), 5 in the bile duct (BD), and 6 in the sinusoid (SS). A histological study confirmed the direct invasion of the macrometastatic cancer cells into the adjacent PV, CV, BD, and SS. According to the tumor doubling time, the mean diameter of the macrometastases in 19 remnant livers was calculated to have been 0.57±0.87 cm at the time of the primary resection. The calculated diameter of 3 of these 19 macrometastases was found to be less than 0.01 cm, the minimum implantable size, indicating that the cancer recurrence in these specimens may have developed from macroscopic metastatic lesions as a satellite, and not from the primary tumor. In 13 patients who received doses of 5250 mg or more of 5 fluorouracil (FU) via the hepatic artery, the cumulative disease-free rate 2 years postoperatively was 100%; this value was 47.6% in 11 patients who received less than 5250 mg of 5 FU via the hepatic artery, and 0% in 39 patients who received no chemotherapy (P<0.005). These results suggest that anatomical hepatic resection for satellite lesions, combined with prophylactic hepatic arterial chemotherapy for micrometastases, decreases the recurrence rate of hepatic metastases in the remnant liver.

Meal induced changes in hepatic and splanchnic circulation: a noninvasive Doppler study in normal humans.

The haemodynamic effects of a meal on the splanchnic and hepatic circulation were evaluated in 30 healthy volunteers, using Doppler ultrasonography. The resistance index (RI) of the superior mesenteric artery and of the left and right intrahepatic arteries, the portal vein blood flow as well as the ratio between maximal velocity in the left and right intrahepatic arteries and the adjacent portal vein were measured initially, then 15, 30, 45, and 60 min after the ingestion of a standard balanced liquid meal. Postprandial haemodynamic changes were maximal 30 min after the meal; at that time, mesenteric artery RI decreased significantly [mean -11% (SEM 14%)] whereas portal vein blood flow increased markedly [mean +79% (SEM 14%)]; a significant increase in hepatic artery RI was observed in both liver lobes. The ratio between maximal velocities of the intrahepatic artery and the intrahepatic portal vein was reduced significantly; this ratio decreased more markedly in the right lobe of the liver. These findings would suggest that there was an adaptation of hepatic artery to portal vein blood flow after a meal. The subsequent increase in intrahepatic portal vein flow velocity was found to be greater in the right lobe of the liver.