Portal Inflow Occlusion Research Articles

Remote preconditioning improves hepatic oxygenation after ischaemia reperfusion injury

Hepatic ischaemia reperfusion injury (IRI) lowers hepatic oxygenation and induces tissue acidosis. Remote ischaemic preconditioning (RIPC) reduces hepatic IRI through increased hepatic blood flow but its effect on hepatic oxygenation and acidosis is not known. This study investigates these effects through near infrared spectroscopy (NIRS). Twenty-four NZ rabbits were grouped into four: sham, RIPC, IRI alone, RIPC + IRI. RIPC was induced through three cycles of 10 min ischaemia and reperfusion to the limb. Total hepatic ischaemia was produced by complete portal inflow occlusion for 25 min. Serum transaminases, bicarbonate and hepatic venous nitrite/nitrate (NO(x) ) levels were measured 2 h postreperfusion. Hepatic oxygenation was monitored with NIRS. At 2 h post reperfusion, IRI alone resulted in reduced mitochondrial oxygenation (CytOx CuA Redox), serum bicarbonate, hepatic venous NO(x) with an increase in serum transaminases and hepatic deoxyhaemoglobin levels. RIPC before IRI caused significant improvement in mitochondrial oxygenation (P = 0.01), increased serum bicarbonate (P = 0.02), hepatic venous NO(x) (P = 0.025) with a decrease in serum transaminases (P = 0.04) and hepatic deoxyhaemoglobin levels (P = 0.03). There was a positive correlation (P = 0.02) between hepatic venous NO(x) levels and mitochondrial oxygenation. RIPC before IRI improves hepatic mitochondrial oxygenation and reduces acidosis and currently undergoing clinical study.

Recent advance in laparoscopic hepatectomy

Laparoscopic hepatectomy (LH) has been an incredible proliferation worldwide. many series have demonstrate that LH decreases intraoperative bleeding, postoperative compliceations and the duration of hospital stay. When compared with open hepatectomy(OP). Since the first LH was reported in 1992, near to 3000 cases have been reported,it's morbidity and mortality are 10. 5% and 0. 3% respectively. There are three terms should be used describe LH: pure laparoscopy, hand-assisted laparoscopy, and hybrid technique. In the beginning of LH, both resections were performed using the ultrasonic dissector and electrocautery,the operation included small wedge resection, liver cyst resection, and liver briopsy, however, while improvements in technology,as harmornic scalpel, endovasculer stapling devices, water jet, LigaSure, TissurLink, Habib etc. With increased experience, surgeons became holder and began to performe larger LH. But the keypoint of LH was use of portal inflow occlusion,and technique of paranchymal transection. Key words: Laparoscopic hepatectomy; Hepatocellular carcinoma; Colorectal cancer liver metastases

Hepatic venous outflow reconstruction using an external iliac vein graft for hepatic malignancies (with video)

Hepatic venous outflow reconstruction after major hepatectomy for advanced hepatic malignancies is often difficult even for experienced surgeons because of difficulties in application of anastomotic techniques and selection of the appropriate graft. We present our approach to hepatic venous reconstruction using an external iliac vein (EIV) graft for patients with hepatic malignancies. The EIV graft was preoperatively assessed using three-dimensional abdominal multidetector computed tomography (MDCT). The EIV graft (3.5-4.5cm) was harvested extraperitoneally through an upper groin incision. First, the inferior vena cava and the EIV graft were sutured at two separate sites by using 6/0 propolypropylene as a traction suture with an operating loupe (×2.5) under hemi-hepatic portal inflow occlusion. The distal end of the right hepatic vein (HV) was then reconstructed using the same technique. Graft patency was confirmed by intraoperative color Doppler ultrasonography (Aloca SSD2000, Japan). The mean reconstruction time was 34±6min. There were no complications related to the HV reconstruction and no mortality. Follow-up MDCT showed patency of the graft in all cases without noticeable caliber change. The EIV graft for hepatic venous outflow reconstruction during hepatic resection is a simple technique with long-term graft patency for major HV reconstruction.

A prospective randomized controlled trial to compare Pringle maneuver, hemihepatic vascular inflow occlusion, and main portal vein inflow occlusion in partial hepatectomy

Background Blood loss during liver resection and the need for perioperative blood transfusions have negative impact on perioperative morbidity, mortality, and long-term outcomes. Methods A randomized controlled trial was performed on patients undergoing liver resection comparing hemihepatic vascular inflow occlusion, main portal vein inflow occlusion, and Pringle maneuver. The primary endpoints were intraoperative blood loss and postoperative liver injury. The secondary outcomes were operating time, morbidity, and mortality. Results A total of 180 patients were randomized into 3 groups according to the technique used for inflow occlusion during hepatectomy: the hemihepatic vascular inflow occlusion group (n = 60), the main portal vein inflow occlusion group (n = 60), and the Pringle maneuver group (n = 60). Only 1 patient in the hemihepatic vascular occlusion group required conversion to the Pringle maneuver because of technical difficulty. The Pringle maneuver group showed a significantly shorter operating time. There were no significant differences between the 3 groups in intraoperative blood loss and perioperative mortality. The degree of postoperative liver injury and complication rates were significantly higher in the Pringle maneuver group, resulting in a significantly longer hospital stay. Conclusions All 3 vascular inflow occlusion techniques were safe and efficacious in reducing blood loss. Patients subjected to hemihepatic vascular inflow occlusion, or main portal vein inflow occlusion responded better than those with Pringle maneuver in terms of earlier recovery of postoperative liver function. As hemihepatic vascular inflow occlusion was technically easier than main portal vein inflow occlusion, it is recommended.

Liver failure after major hepatic resection

The consequence of excessive liver resection is the inexorable development of progressive liver failure characterised by the typical stigmata associated with this condition, including worsening coagulopathy, hyperbilirubinaemia and encephalopathy. The focus of this review will be to investigate factors contributing to hepatocyte loss and impaired regeneration. A literature search was undertaken of Pubmed and related search engines, examining for articles relating to hepatic failure following major hepatectomy. In spite of improvements in adjuvant chemotherapy and increasing surgical confidence and expertise, the parameters determining how much liver can be resected have remained largely unchanged. A number of preoperative, intraoperative and post-operative factors all contribute to the likelihood of liver failure after surgery. Given the magnitude of the surgery, mortality and morbidity rates are extremely good. Careful patient selection and preservation of an obligate volume of remnant liver is essential. Modifiable causes of hepatic failure include avoidance of sepsis, drainage of cholestasis with restoration of enteric bile salts and judicious use of portal triad inflow occlusion intra-operatively. Avoidance of post-operative sepsis is most likely to be achieved by patient selection, meticulous intra-operative technique and post-operative care. Modulation of portal vein pressures post-operatively may further help reduce the risk of liver failure.

A clinical comparative analysis of crush/clamp, stapler, and dissecting sealer hepatic transection methods

Introduction. Several methods for hepatic parenchymal division exist. The primary aim was to assess differences in postoperative bile leaks, operative blood loss, and margin status between three transection methods: crush/clamp (CC), stapler (SP), or dissecting sealer (DS). Methods. A single institution, retrospective cohort study was performed on data collected over a three-year period in patients undergoing elective liver resection using the CC, SP, or DS. Patients were excluded if multiple methods of transection were used or for intraoperative death. The association of bile leak with transection type was assessed. A logistic regression model was tested to assess if blood loss was associated with the covariates of transection method, use of portal inflow occlusion, extent of liver resection, and other concurrent major operations. Results. Analyses included 141 patients. The stapler method was quicker than the other methods (p=0.01). The risk of postoperative bile leak was no different between CC, SP, and DS transection methods (p=0.23). There was no difference in mean blood loss or transfusions; however, hepatectomies performed with DS were associated with an increased risk of blood loss ≥1000mL compared to CC (p=0.04). There were no differences in mean surgical margin between the three methods. Conclusion. The risk of bile leaks was not different between the three methods. While mean blood loss was similar, hepatectomy performed with the DS was associated with an increased risk of having operative blood loss ≥1000mL compared to CC. Margins were equal by all methods. The stapler method was quicker.

The application of selective portal inflow occlusion in laparoscopic hepatectomy

To discuss the safety and the feasibility of laparoscopic selective portal inflow occlusion. From January 2005 to February 2006, 7 patients were performed by laparoscopic hepatectomy with selective portal inflow occlusion. The patients included 1 male and 6 females, the mean age was 48.9 years, ranged from 31 to 70 years. Procedure included left lateral segmentectomies (4 patients), left hemihepatectomies (2 patients), and right hemihepatectomies (1 patient). Portal vein, hepatic artery and their branches were exposed by blunt dissection and performed selective portal occlusion with absorbable clips. There is no conversion, no mortality, and no postoperative complication. Seven selective portal inflow occlusions were performed successfully. The mean operating time was 188.7 min (range 70 min to 300 min), the mean intraoperative blood loss was 625 ml (range 350 ml to 1000 ml), and the mean postoperative hospital stay was 8.4 days. Laparoscopic selective portal inflow occlusion is a safe and feasible technique.

One hundred and fifty hepatic resections: evolution of technique towards bloodless surgery.

A technique of hepatic resection is described and the results of 150 resections are reviewed. Hepatic transection was performed, under intermittent portal inflow occlusion, using ultrasonic aspiration to skeletonize portal branches and venous tributaries. Control of venous haemorrhage during resection was optimized by argon beam coagulation and lowering central venous pressure to between 0 and 4 cmH2O by extradural blockade and systemic nitroglycerine infusion. One patient with jaundice died in hospital, giving a mortality rate of 0.7 per cent. There were no deaths in patients without jaundice and cirrhosis. Fifteen patients (10.0 per cent) had significant complications, nine medical and six surgical, including three bile leaks (2.0 per cent). Mean blood loss was 814 ml for the whole study but only 434 ml in the last 4 years. During this latter period mean blood transfusion in hospital was 0.5 units and mean postoperative haemoglobin value fell by 0.7 g per 100 ml. Hepatic resection can be performed with the same degree of confidence and similar low morbidity as any other major surgical procedure.

The effect of hepatic blood inflow occlusion on hepatic cancer treated with diode-laser thermocoagulation

To assess the effect of temporary occlusion of hepatic blood inflow on hepatic cancer treated with diode-laser induced thermocogation (LITT). The carcinoma Walker-256 was implanted in 40 SD rat livers. Twelve days later, the animals were randomly divided into 4 groups. Group A received LITT alone; group B received hepatic artery temporary occlusion during LITT; group C received portal vein temporary occlusion during LITT; group D received hepatic artery and portal vein temporary occlusion during LITT. Tumors were exposed to 810 nm diode-laser light at 0.95 watts for 10 min from a scanner tip applicator placed in the tumor. At the same time, the intrahepatic temperature distribution in rats with liver tumors was measured per 2 min during thermocoagulation. Tumor control was examined immediately 7 and 14 d after thermocoagulation. There was significant difference of intrahepatic temperature distribution in rats with liver tumors among the 4 groups (P<0.05) except when group C samples were compared with group D samples at each time point, and group B samples were compared with group C samples at 120 s (P>0.05). Light microscopic examination of the histologic section samples revealed three separate zones: regular hyperthermic coagulation necrosis zone, transition zone and reference zone. Compared with the samples in group A and group B, group C and group D samples had more clear margin among the three zones. The hepatic blood inflow occlusion, especially portal vein hepatic blood inflow occlusion, or all hepatic blood inflow occlusion considerably increased the efficacy of LITT in the treatment of liver cancer.

Ｈｓ肝細胞癌に対する選択的肝阻血法を用いた系統的肝亜区域切除術による長期予後の改善

Ｈｓ肝細胞癌に対する選択的肝阻血法を用いた系統的肝亜区域切除術による長期予後の改善

Metabolic activity and DNA integrity in human hepatic metastases after interstitial laser coagulation (ILC)

Background and Objective For investigations into interstitial laser coagulation (ILC) of solid tumors, tissue whitening is used as a parameter for the extent of coagulation. This obvious demarcation is associated with global thermal denaturation, but it is not clear whether this finding is a good indicator of the exact outer boundary of the lethal tissue effect. Study Design/Materials and Methods ILC with portal inflow occlusion was performed in human hepatic metastases of colorectal carcinoma directly after surgical resection (n = 5) or before surgical resection (n = 5) with laser parameters adapted to tumor diameter. Mitochondrial NADH-diaphorase activity and DNA integrity were assessed by histoenzymatic staining. Results In 7 of 10 tumors (mean diameter, 3.7 cm), an area of macroscopic coagulation (mean diameter, 4.2 cm) encircled the tumor in all three axes. Macroscopic coagulation corresponded to absent metabolism and disintegrated DNA. Furthermore, the macroscopic volumes of coagulation produced in tumor were comparable to the dimensions in normal porcine liver with the same laser parameters. Conclusion ILC with portal inflow occlusion results in areas with complete cell avitality in the zone of tissue whitening in human hepatic liver metastases. Lasers Surg. Med. 28:80–86, 2001. © 2001 Wiley-Liss, Inc.

Experimental study of a novel fibrin sealant for achieving haemostasis following partial hepatectomy.

Ensuring adequate haemostasis is a major difficulty in the field of liver surgery. This study aimed to evaluate a novel fibrin sealant (Vivostat), designed for autologous preparation, in a porcine model of partial hepatectomy. Thirty-six Large White Landrace pigs underwent partial left hepatectomy by finger fracture under portal vascular inflow occlusion. Animals were randomized to treatment of the resected surface with either fibrin sealant (Vivostat, n = 12) or regenerated oxidized cellulose gauze (Surgicel, n = 12), or were left untreated (controls, n = 12). Blood loss from the resection margin was measured at 2-min intervals for 10 min, and the time to haemostasis was recorded. Following complete haemostasis the animals recovered for 7 days. Median (range) blood loss in the control group was 94.3 (17.3-467.0) g, and was significantly reduced with Vivostat (13.8 (5.5-150.9) g) and Surgicel (22.8 (5.8-67.3) g). Median (range) time to haemostasis in controls (31 (12-52) min) was also significantly reduced by Vivostat (8 (0-32) min) and Surgicel (10 (0-19) min) (both P < 0.001 versus controls, Kruskal-Wallis test). The novel fibrin sealant, Vivostat, is as effective as Surgicel cellulose gauze in achieving haemostasis after porcine partial hepatic lobectomy.

Metabolic activity and DNA integrity in human hepatic metastases after interstitial laser coagulation (ILC).

For investigations into interstitial laser coagulation (ILC) of solid tumors, tissue whitening is used as a parameter for the extent of coagulation. This obvious demarcation is associated with global thermal denaturation, but it is not clear whether this finding is a good indicator of the exact outer boundary of the lethal tissue effect. ILC with portal inflow occlusion was performed in human hepatic metastases of colorectal carcinoma directly after surgical resection (n = 5) or before surgical resection (n = 5) with laser parameters adapted to tumor diameter. Mitochondrial NADH-diaphorase activity and DNA integrity were assessed by histoenzymatic staining. In 7 of 10 tumors (mean diameter, 3.7 cm), an area of macroscopic coagulation (mean diameter, 4.2 cm) encircled the tumor in all three axes. Macroscopic coagulation corresponded to absent metabolism and disintegrated DNA. Furthermore, the macroscopic volumes of coagulation produced in tumor were comparable to the dimensions in normal porcine liver with the same laser parameters. ILC with portal inflow occlusion results in areas with complete cell avitality in the zone of tissue whitening in human hepatic liver metastases.

Long-term Effects of Interstitial Laser Coagulation in Porcine Liver with Portal Inflow Occlusion: Central versus Peripheral Lesions

Interstitial laser coagulation (ILC) is an attractive modality for local destruction of unresectable hepatic metastases. Portal inflow occlusion considerably increases its destructive capacity, resulting in lesions 5 cm in diameter; however, effects on adjoining major intrahepatic structures are unknown. Therefore, the purpose of this study was to assess the effects of ILC with portal inflow occlusion on the central portion of the liver as compared to the peripheral portions. ILC was performed in pigs with portal inflow occlusion. Each animal received a single laser application with Nd:YAG light guided simultaneously through four interstitial fibers with 5 W per fiber during 6 minutes. Location of treatment was randomized to either central (n = 8) or peripheral (n = 8). Follow-up was for 1, 2, or 3 months with evaluation of liver functions and weight, as well as macroscopic and microscopic assessment of coagulated lesions and surrounding parenchyma. There was no treatment-related morbidity or mortality. No obstructive cholestasis or bile leakage was found. At every moment of evaluation, coagulated volumes in the central group were smaller than in the peripheral lesions (P = .03). Large vessels contiguous to the lesions in the central group were always intact and indications of portal hypertension or thrombosis of hepatic veins were not found. There were no significant differences between the two groups (liver functions [P > or = .15] and weight [P = .69]). ILC with portal inflow occlusion is a safe technique in the vicinity of vital structures in the liver of healthy pigs. These results justify studies to the feasibility and complication rate of portal inflow occlusion in patients with hepatic malignancies.

Percutaneous Radiofrequency Tissue Ablation: Does Perfusion-mediated Tissue Cooling Limit Coagulation Necrosis?

To determine, by decreasing hepatic perfusion during radiofrequency (RF) ablation, whether perfusion-mediated tissue cooling can explain the reduced coagulation observed in in vivo studies compared to that seen with RF application in ex vivo tissue. RF was applied in vivo with use of cooled-tip electrodes to normal porcine liver without (n = 8) and with balloon occlusion of the portal vein (n = 8), celiac artery (n = 3), or hepatic artery (n = 2), and to ex vivo calf liver (n = 10). In vivo trials of vasopressin (0.3-0.6 U/min) infusion during RF application with (n = 10) and without (n = 2) arterial balloon occlusion were also performed. Intraoperative RF was subsequently performed in seven patients with hepatic colorectal metastases with and without portal inflow occlusion. Remote thermometry was performed in four patients. RF application (12 minutes) during portal venous occlusion produced larger areas of coagulation necrosis than RF with unaltered blood flow (2.9 cm +/- 0.1 vs 2.4 cm +/- 0.2 diameter; P < .01). With celiac and hepatic artery occlusion, coagulation diameter measured 2.7 cm +/- 0.2 and 2.5 cm +/- 0.1, respectively. Infusion of vasopressin without vascular occlusion reduced coagulation diameter to 1.1 cm. However, different methods of hepatic or celiac arterial balloon occlusion with simultaneous vasopressin infusion produced a mean 3.4 cm +/- 0.2 of necrosis. Coagulation in ex vivo liver was 2.9 cm +/- 0.1 in diameter. Clinical studies demonstrated greater coagulation diameter for metastases treated during portal inflow occlusion (4.0 cm +/- 1.3) than for tumors treated with normal blood flow (2.5 cm +/- 0.8; P < .05). Thermometry documented a 10 degrees C increase compared to baseline at 10 mm and 20 mm from the electrode after 5 minutes of portal inflow occlusion during constant RF application. Perfusion-mediated tissue cooling reduces coagulation necrosis achievable with RF ablation. Reduction of blood flow during RF application increases coagulation in both an animal model and human liver metastases.

The safety of total hepatic vascular occlusion in rabbits with acute extrahepatic cholestasis.

The technique of normothermic total hepatic vascular occlusion (THVO) is achieved by concomitant clamping of the inferior vena cava above and below the liver in addition to portal inflow occlusion. In this study we investigated the use of THVO for 45 min in a rabbit model with acute cholestasis of 10 days' duration. In rabbits with normal preoperative liver functions (control group), serum total bilirubin, glutamic-pyruvic transaminase (SGPT), glutamic-oxaloacetic transaminase (SGOT), alkaline phosphate, and gamma-glutamyltranspeptidase levels returned to normal ranges within a week after THVO. In the group with persistent cholestasis THVO was performed 10 days after ligation of the extrahepatic bile duct. Total bilirubin and canalicular enzymes remained high while the SGOT and SGPT peaked and almost returned to the preoperative levels at 7 days following THVO in this group. A third group of animals also underwent THVO 10 days after ligation of their extrahepatic bile ducts with relief of the obstruction with a Teflon stent immediately after THVO. This group also showed the trend of normalization of liver canalicular and parenchymal enzymes and bilirubin by the end of 7 days. This study demonstrated the feasibility of THVO in rabbits with acute extrahepatic cholestasis whether the extrahepatic biliary obstruction persisted or not.