Hepatic Vascular Inflow Occlusion Research Articles

Is the Pringle manoeuvre becoming a lost art? Contemporary use for both severe liver trauma with ongoing hemorrhage and elective partial hepatectomy

SummaryThe Pringle manoeuvre (vascular inflow occlusion) has been a mainstay technique in trauma surgery and hepato-pancreato-biliary surgery since it was first described in the early 1900s. We sought to determine how frequently the manoeuvre is used today for both elective and emergent cases in these disciplines. To reflect on its evolution, we evaluated the Pringle manoeuvre over a recent 10-year period (2010–2020). We found it is used less frequently owing to more frequent nonoperative management and more advanced elective hepatic resection techniques. Continuing educational collaboration is critical to ensure continued insight into the impact of hepatic vascular inflow occlusion among trainees who observe this procedure less frequently.

Intermittent regional hepatic vascular inflow occlusion for laparoscopic right anterior sectionectomy

Objective To compare the efficacy and safety of intermittent regional hepatic vascular inflow occlusion with Pringle’s maneuvre for laparoscopic anterior sectionectomy. Methods From January 2014 to December 2018, 54 patients who underwent laparoscopic right anterior sectionectomy at the Department of Hepatopancreatobiliary Surgery, the Third Affiliated Hospital, Soochow University were recruited into this study. The patients were 40 to 60 years old, and 27 were males and 27 females. Intermittent regional hepatic vascular inflow occlusion was carried out in 24 patients (the intermittent occlusion group). The remaining patients underwent Pringle’s maneuvre (the Pringle group). Postoperative liver function, intraoperative blood loss, intraoperative blood transfusion, operation time and postoperative complications between the two groups were compared. Results Intraoperative hemorrhage and blood transfusion of the Pringle group (534±42)ml, (2.88±0.54)U were significantly higher than the intermittent occlusion group (374±21)ml, (1.86±0.29)U (all P 0.05). Conclusion Intermittent regional hepatic vascular inflow occlusion reduced intra-operative hemorrage and hepatic impairment, and shortened hospital stay. However, it required higher operation skills and it should gradually be promoted. Key words: Hepatectomy; Laparoscopes; Inflow occlusion; Liver function

A Propensity score analysis of two methods of hepatic vascular occlusion in hepatectomy

Abstract Background The key points in hepatectomy are reducing blood loss and preservation of hepatic function. The aim of this study was to compare the perioperative outcomes of partial hepatectomy using two techniques of hepatic vascular inflow occlusion. Materials and methods A total of 1817 patients were selected from our multi-institutional hepatectomy database in China and classified into two groups: the hemihepatic inflow occlusion (HIO) group ( n = 1693) and the ipsilateral portal vein branch occlusion (IPVBO) group ( n = 124). Propensity score matching of patients in a ratio of 1:1 was conducted. The primary outcome was intraoperative blood loss. Secondary outcomes were postoperative liver function, postoperative morbidity and mortality, and duration of hospital stay after surgery. Results After propensity score matching, there were 124 patients in the IPVBO group and the HIO group, respectively. There were no significant differences between the two groups regarding intraoperative blood loss, blood transfusion requirement, operating time, postoperative morbidity and mortality, and duration of hospital stay after surgery ( P > 0.05). However, The IPVBO group was associated with significantly lower peak in postoperative ALT level than the HIO group ( P Conclusions The results indicated that IPVBO did not lead to more intraoperative blood loss compared with HIO, and it decreased the peak of postoperative ALT level. In terms of postoperative morbidity and mortality, duration of hospital stay after surgery, IPVBO was also equal to HIO. Thus, IPVBO could be an alternative method of hepatic inflow occlusion.

A propensity score analysis of two methods of hepatic vascular occlusion in hepatectomy

BackgroundThe key points in hepatectomy are reducing blood loss and preservation of hepatic function. The aim of this study was to compare the perioperative outcomes of partial hepatectomy using two techniques of hepatic vascular inflow occlusion. Materials and methodsA total of 1817 patients were selected from our multi-institutional hepatectomy database in China and classified into two groups: the hemihepatic inflow occlusion (HIO) group (n = 1693) and the ipsilateral portal vein branch occlusion (IPVBO) group (n = 124). Propensity score matching of patients in a ratio of 1:1 was conducted. The primary outcome was intraoperative blood loss. Secondary outcomes were postoperative liver function, postoperative morbidity and mortality, and duration of hospital stay after surgery. ResultsAfter propensity score matching, there were 124 patients in the IPVBO group and the HIO group, respectively. There were no significant differences between the two groups regarding intraoperative blood loss, blood transfusion requirement, operating time, postoperative morbidity and mortality, and duration of hospital stay after surgery (P > 0.05). However, The IPVBO group was associated with significantly lower peak in postoperative ALT level than the HIO group (P < 0.05). ConclusionsThe results indicated that IPVBO did not lead to more intraoperative blood loss compared with HIO, and it decreased the peak of postoperative ALT level. In terms of postoperative morbidity and mortality, duration of hospital stay after surgery, IPVBO was also equal to HIO. Thus, IPVBO could be an alternative method of hepatic inflow occlusion.

A single-centre experience of 200 laparoscopic liver resections

Objective To summarize the clinical experience of laparoscopic liver resection (LLR) for liver benign and malignant tumors. Methods Retrospective analysis was performed to review the pooled data of 200 patients treated with laparoscopic liver resection from Qilu Hospital between June 2012 and November 2015. These patients were assigned into left liver group (n=108) and right liver group (n=86) by tumor sites. The clinical data obtained from the two groups was compared in the aspect of patients' general information, surgical indicators and postoperative blood workup. Results There was no significant difference in the clinical data between the two groups. The operation duration and post-operative hospitalized days in the group R were significantly longer than those in the group L [(165.5±61.2) min vs. (135.6±62.5) min, P<0.05 for operative duration; (11.3±4.3)d vs. (9.4±4.8)d, P<0.05 for post-operative hospitalized days]. Blood loss in the group R was significantly more than that in the group L[(299.0±352.9)ml vs. (144.3±160.0)ml, P<0.05]. Hepatic vascular inflow occlusion was more frequently used in laparoscopic right liver resection, the average duration of this procedure was (24.5±7.3) min. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) elevated on day 1 and day 3 after LLR in both groups, with significant differences observed between the two groups. There was no statistical difference in prothrombin time (PT) of patients between the two groups. Conclusions This study suggests that laparoscopic liver resection is safe and effective in the management of liver neoplams. Compared with left liver group, the right liver group has been associated with inferior clinical outcomes of surgery complexity, operation duration, blood loss, postoperative hospitalization days, hepatic vascular inflow occlusion, and postoperative ALT and AST levels. Key words: Laparoscopy; Liver resection; Liver neoplasm; Experience

Hepatic vascular inflow occlusion is associated with reduced disease free survival following resection of colorectal liver metastases

BackgroundHepatic vascular inflow occlusion (VIO) can be applied during resection of colorectal liver metastases (CRLM) to control intra-operative blood loss, but has been linked to accelerated growth of micrometastases in experimental models. This study aimed to investigate the effects of hepatic VIO on disease-free and overall survival (DFS and OS) in patients following resection for CRLM. MethodsAll patients who underwent liver resection for CRLM between January 2006 and September 2015 at our center were analyzed. Hepatic VIO was performed if deemed indicated by the operating surgeon and severe ischemia was defined as ≥20 min continuous or ≥45 min cumulative intermittent VIO. Cox regression analysis was performed to identify predictive factors for DFS and OS. ResultsA total of 208 patients underwent liver resection for CRLM. VIO was performed in 64 procedures (31%), and fulfilled the definition of severe ischemia in 40 patients. Patients with severe ischemia had inferior DFS (5-year DFS 32% vs. 11%, P < 0.01), and inferior OS (5-year OS 37% vs. 64%, P < 0.01). At multivariate analysis, a high clinical risk score (Hazard ratio (HR) 1.60 (1.08–2.36)) and severe ischemia (HR 1.89 (1.21–2.97)) were independent predictors of worse DFS. Severe ischemia was not an independent predictor of OS. ConclusionThe present cohort study suggests that prolonged hepatic VIO during liver resection for CRLM was associated with reduced DFS. A patient-tailored approach seems advisable although larger studies should confirm these findings.

A prospective randomized controlled trial: Comparison of two different methods of hepatectomy

BackgroundHemorrhage and liver failure are the two major complications in partial hepatectomy. The finger fracture or clamp crushing technique has been a standard technique used for transection of liver parenchyma. Hepatic vascular Inflow occlusion (Pringle maneuver, PM) is often used to minimize blood loss, but hepatic ischemia-reperfusion may result with an increased risk of post-operative liver failure. The Harmonic scalpel (HS) has been shown to be effective in reducing blood loss during liver parenchymal transection without any hepatic vascular inflow occlusion. MethodsA randomized controlled trial was carried out to evaluate the impact of the two different hepatic transection techniques. The post-operative short-term results were compared. ResultsDuring the study period, 160 of 212 patients who received partial hepatectomy in our hospital were randomized into 2 groups: the PM group (n = 80) and the HS group (n = 80). The numbers of patient who had a poor liver function on post-operative day 5 (ISLGS Grade B) were 30, and 18, respectively (p < 0.05). The post-operative complication rate was significantly higher in the PM group (41.3% versus 22.5%, p < 0.05). The HS group had significantly less blood loss and blood transfusion requirements than the PM group (p < 0.05). ConclusionsIn conclusion, liver resection carried out using HS without hepatic vascular occlusion was better than using finger fracture or clamp crushing technique with Pringle maneuver. The use of HS allowed liver resection to be safely performed, with earlier recovery of liver function, and less surgical complication.

A Prospective Randomized Controlled Trial to Compare Pringle Manoeuvre with Hemi-hepatic Vascular Inflow Occlusion in Liver Resection for Hepatocellular Carcinoma with Cirrhosis

BackgroundThe duration of hepatic vascular inflow occlusion and the amount of intraoperative blood loss have significant negative impacts on postoperative morbidity, mortality and long-term survival outcomes of patients who receive partial hepatectomy for hepatocellular carcinoma (HCC) with cirrhosis. AimThis study aimed to compare the perioperative outcomes of partial hepatectomy for HCC superimposed on hepatitis B-related cirrhosis using two different occlusion techniques. MethodsA randomized controlled trial was carried out to evaluate the impact of two different vascular inflow occlusion techniques. The postoperative short-term results were compared. ResultsDuring the study period, 252 patients received partial hepatectomy for HCC with cirrhosis. Of these patients, 120 were randomized equally into two groups: the Pringle manoeuvre group (n = 60) and the hemi-hepatic vascular inflow occlusion group (n = 60). The number of patients who had poor liver function on postoperative day 5 with ISLGS grade B or worse was 24 and 13, respectively (P = 0.030). The postoperative complication rate was significantly higher in the Pringle manoeuvre group (40 versus 22 %, P = 0.030). However, the Pringle manoeuvre group had significantly shorter operating time (116 versus 136 min, P = 0.012) although there was no significant difference in intraoperative blood loss between the two groups [200 ml (range 10–5,000 ml) versus 300 ml (range 100–1,000 ml); P = 0.511]. There was no perioperative mortality. ConclusionsThe results indicated that for patients with HCC with cirrhosis, hemi-hepatic vascular inflow occlusion was a better inflow occlusion method than Pringle manoeuvre.

Regional hepatic vascular inflow occlusion in laparoscopic hepatectomies

Objective To explore the feasibility and safety of regional hepatic vascular inflow occlusion in laparoscopic hepatectomies.Methods 35 patients with liver lesions received laparoscopic hepatectomy using regional hepatic vascular inflow occlusion.The mean age was 46.1 ± 3.5 years.The relevant branches of portal vein and hepatic artery were isolated with sharp and blunt dissections and were then occluded regionally.Results Laparoscopic regional hepatic vascular inflow occlusion and hepatectomies were successfully carried out in 35 patients.The mean operative time was 60.6±15.2 minutes.The mean blood loss was 230.8±56.5 ml.The mean postoperative hospital stay was 6.6±1.3 days.Conclusions Regional hepatic vascular inflow occlusion is a safe and feasible method in laparoscopic hepatectomies. Key words: Hepatectomy; Laparoscopic; Hepatic blood inflow; Occlusion

Comparison of Internally Cooled Wet Electrode and Hepatic Vascular Inflow Occlusion Method for Hepatic Radiofrequency Ablation

Background/AimsVarious strategies to expand the ablation zone have been attempted using hepatic radiofrequency ablation (RFA). The optimal strategy, however, is unknown. We compared hepatic RFA with an internally cooled wet (ICW) electrode and vascular inflow occlusion.MethodsEight dogs were assigned to one of three groups: only RFA using an internally cooled electrode (group A), RFA using an ICW electrode (group B), and RFA using an internally cooled electrode with the Pringle maneuver (group C). The ablation zone diameters were measured on the gross specimens, and the volume of the ablation zone was calculated.ResultsThe ablation zone volume was greatest in group B (1.82±1.23 cm3), followed by group C (1.22±0.47 cm3), and then group A (0.48±0.33 cm3). The volumes for group B were significantly larger than the volumes for group A (p=0.030). There was no significant difference in the volumes between groups A and C (p=0.079) and between groups B and C (p=0.827).ConclusionsBoth the usage of an ICW electrode and hepatic vascular occlusion effectively expanded the ablation zone. The use of an ICW electrode induced a larger ablation zone with easy handling compared with using hepatic vascular occlusion, although this difference was not statistically significant.

Selective main portal vein clamping to minimize the risk of recurrence after curative liver resection for hepatocellular carcinoma.

Our aim was to compare the postoperative outcomes of partial hepatectomy using Pringle maneuver and selective main portal vein clamping. From January 2004 to December 2006, 169 consecutive patients received liver resection by the same surgical team. The surgical techniques were the same for all patients except for the hepatic vascular inflow occlusion techniques during liver parenchymal transection. Patients either received clamping of the portal triad (PTC group, n=118) or selective main portal vein clamping (PVC group, n=51). Operative time to carry out PVC was significantly longer than PTC (110.6±21.8 vs. 129.6±29.8min), however intraoperative blood loss was the same. There was no significant difference in operative mortality or morbidity rates, although the liver function recovered quicker in the PVC group. Significantly more patients in the PTC group developed HCC recurrence at postoperative one year than the PVC group (60.2% vs. 33.3%). There was no significant difference in overall survival between the 2 groups. Univariate analysis showed that clamping method, tumor size and BCLC grade were risk factors for disease-free survival (DFS) at one year, and multivariate analyses demonstrated clamping method and AFP level as independent risk factors for DFS. Patients subjected to selective portal vein clamping did better than those to Pringle maneuver in the postoperative outcomes. The underlying mechanism may be I/R injury of the liver remnant which might also contribute to an increase in tumor recurrence after liver resection.

The impact of different hepatic vascular occlusion methods on hepatic parenchymal function in partial hepatectomy

Objective To investigate the impact of different hepatic vascular inflow occlusion methods on hepatic parenchymal function in partial hepatectomy.Methods Between 2009 and 2010,62 hepatocellular carcinoma (HCC) patients underwent partial hepatectomy.In 13 patients,partial hepatectomy was carried out without using any inflow occlusion (group A).In 29 patients intermittent Pringle's maneuver (group B) while in 20 patients selective hepatic inflow occlusion (group C) were used.Intraoperative indocyanine green retention rate at 15 minutes (ICGR15) was measured using pulse spectrophotometry before and during hepatectomy. Results (1) Blood loss in group A was greater than group B and C (P=0.016,P=0.001).(2) There was no significant difference in the preoperative ICGR15 values among group A,B and C.The intraoperative ICGR15 for group B was significantly higher than group A and C (P=0.011,P=0.030).(3) A significant correlation was found between the level of ICGR15 and total inflow clamp time (r =0.484,P =0.001) and blood loss (r=0.349,P=0.005),respectively.(4) Compared with group A and B,postoperative liver function recovered significantly faster in group C.Conclusion Selective hepatic inflow occlusion was useful in controlling blood loss and it was beneficial to the hepatic functional reserve in the liver remnant. Key words: Hepatocellular carcinoma; Hepatectomy; Indocyanine green; Hepatic inflow occlusion; Liver function reserve

Liver hanging maneuver and selective total hepatic vascular inflow and outflow occlusion in hemi-hepatectomy

术中出血是肝切除术的主要风险,与术后并发症及手术病死率密切相关[1].肝脏血流控制是减少肝切除术中出血的主要手段[2].目前控制方法虽多,但常发生残余肝脏缺血-再灌注损伤、血流阻断不完全等[3-6]问题.从2006年开始我们对肝悬吊法(liver hanging maneuver)联合选择性出入肝血流阻断技术在减少肝切除术中出血及改善手术预后中的作用进行了探讨。

Multivariate regression analysis of factors influencing complications after liver resection for hepatocellular carcinoma

Objective To analysis of risk factors influencing complications after liver resection for hepatocellular carcinoma. Methods The clinical data of 110 hepatocellular carcinoma cases who underwent liver resection were retrospectly analyzed by univariate and multivariate analyses. Results There were 38 patients (34. 5%)represented main complications after operation. Singlevaraite analysis showed that thelevel of HBVD-NAand Prealbumin, Child stage, prothrombin time, the hepatic vascular inflow occlusion, total blood loss were proved to be risk factors for complications after liver resection for hepatocellular carcinoma;Multivariate logistic analysis showed that the level of Prealbumin, Child stage and total blood loss were the independent risk factors.Conclusion Preoperation liver function and total blood loss during the operation are the main factors influencing complications after liver resection for hepatocellular carcinoma. Key words: Hepatic carcinoma; Complication

The Effect of Hepatic Vascular Inflow Occlusion on Liver Tissue pH, Carbon Dioxide, and Oxygen Partial Pressures: Defining the Optimal Clamp/Release Regime for Intermittent Portal Clamping

The optimal duration of hepatic vascular inflow occlusion (Pringle maneuver) and reperfusion during liver resection are not defined. The aim of this study was to describe the changes that occur in liver tissue pH, partial pressure of carbon dioxide (P(L)CO(2)), and partial pressure of oxygen (P(L)O(2)) and by using the P(L)CO(2) as a predictor of hepatocellular damage define the optimal clamp/release regime for intermittent portal clamping during liver resection. Continuous pH, P(L)CO(2), and P(L)O(2) measurements were obtained using a Paratrend multi-parameter sensor (Diametrics Medical Inc., Roseville, MN) in 13 patients undergoing elective partial liver resection. Patients were randomly allocated to undergo a 10-min clamp/5-min release regime (group 1) or a 20-min clamp/10-min release regime (group 2). In group 1 (n = 6) P(L)CO(2) increased and pH decreased significantly after 10 min of clamping and returned to baseline within 5 min of reperfusion. In group 2 (n = 7) the P(L)CO(2) increased and pH decreased significantly after 10 min of clamping, with a further significant change after 20 min. Following 10 min of reperfusion, pH and P(L)CO(2) had not returned to baseline. P(L)O(2) did not change significantly with either intermittent portal clamping regime. A reperfusion of 5 min is sufficient to restore the P(L)CO(2) and liver tissue pH to normal after 10 min of clamping, but more than 10 min of reperfusion is required after 20 min of clamping. To minimize hepatic ischemia during liver resection, a 10-min clamp/5-min release regime should be used.

Hepatic vascular inflow occlusion enhances tissue destruction during cryoablation of porcine liver 1

Background Local recurrences after cryoablation of liver tumors have been reported at rates from 5% to 44% and can be caused by inadequate coverage of the tumor by the frozen region. Hepatic vascular inflow occlusion may facilitate ablation by enlarging the size of the frozen region and the tissue necrosis induced by freezing. Few studies have documented these effects of inflow occlusion during liver cryoablation. Materials and methods Two cryolesions were induced in the liver of 12 pigs in a standardized set-up. Vascular inflow occlusion was used in six pigs during freezing. Two freeze cycles were performed at each location. Ice-ball volume was estimated by intraoperative magnetic resonance imaging. Cryolesion volume was estimated from histopathologic examination of the lesions 4 days after ablation. Results The median volume of ice-balls produced during inflow occlusion was 107% larger than for ice-balls produced without occlusion ( P < 0.001). The median volume of cryolesions made during inflow occlusion was 195% larger than for cryolesions induced without occlusion ( P < 0.001). The geometry of the ice-balls was more regular if produced during inflow occlusion than if not. The ice-balls produced during the second freeze cycle were 17% and 20% larger than the ice-ball produced during the first freeze for lesions made with ( P = 0.01) and without ( P = 0.03) inflow occlusion. Conclusions Hepatic vascular inflow occlusion enables freezing of larger volumes of liver tissue andincreases the volume of tissue necrosis induced during cryoablation of porcine liver.

Intraoperative contrast-enhanced MR-imaging as predictor of tissue damage during cryoablation of porcine liver.

This study evaluate intraoperative Magnetic Resonance Imaging (MRI) as predictor of tissue damage following cryoablation of porcine liver with and without concomitant hepatic vascular inflow occlusion. Inflow occlusion was used during freezing in 6 of 12 pigs included. The volumes of the procedural ice-balls were estimated from MR images. Immediately after thawing contrast (MnDPDP) enhanced MRI was performed to estimate the volume of the cryolesion. Four days after ablation MRI was repeated of the in-vivo and the ex-vivo liver. Photography was performed of the sliced liver specimens to estimate the volumes of the lesions. The intraoperative volume of the cryolesion as shown by contrast enhanced MRI corresponded well to the ice-ball volume for lesions made without vascular occlusion (difference 0.3 +/- 0.9 cm(3), p = 0.239). For lesions made during occlusion the volume of the intraoperative cryolesion was larger than the corresponding ice-ball (difference 7.5 +/- 3.3 cm(3), p = 0.003). The volume of the cryolesions as estimated from histopathology four days after freezing and contrast enhanced MRI immediately after freezing corresponded well for lesions made with (difference -2.6 +/- 4.5 cm(3), p = 0.110) and without vascular occlusion (difference -0.5 +/- 2.3 cm(3), p = 0.695). Intraoperative MnDPDP-enhanced MRI of the cryolesion is predictive of the tissue damage induced during cryoablation of porcine liver. The procedural ice-ball is not, if induced during inflow occlusion.

Radiofrequency tissue ablation: effect of hepatic blood flow occlusion on thermal injuries produced in cirrhotic livers.

Radiofrequency thermal ablation has been used as a treatment for several types of hepatic malignancies. Many of these lesions exist in the presence of cirrhosis. Limitations exist to the size of the ablations and, subsequently, the efficacy of treatment. Hepatic vascular inflow occlusion has been advocated as an adjunctive measure to increase the efficacy of the ablation. We present a model in the human cirrhotic liver that demonstrates the advantage of blood flow occlusion during radiofrequency ablation. Five patients with advanced endstage liver disease scheduled to have orthotopic liver transplantation were enrolled in this study. After laparotomy and before hepatectomy, radiofrequency ablation was performed without and with hepatic blood flow occlusion. After hepatectomy, the liver was sectioned, the area of ablation was measured in three dimensions, and the volume of ablation calculated. Three of the patients had had previously placed transjugular intrahepatic portosystemic shunt. The mean volume of the ablation without blood flow occlusion was 22.5 +/- 7.4 cm(3) and that with blood flow occlusion was 48.4 +/- 24.0 cm(3) (P =.05). Ablation area is increased significantly with hepatic blood flow occlusion in the human cirrhotic liver. This result may have application in the treatment of larger (>3 cm) hepatic malignancies.

Changes in tissue oxygenation of the porcine liver measured by near-infrared spectroscopy.

Near-infrared spectroscopy (NIRS) is a novel method for the measurement of tissue oxygenation and may have a role in monitoring liver oxygenation and viability. The aim of this study is to validate the application of NIRS for monitoring hepatic tissue oxygenation. Large Landrace pigs (n = 12) underwent laparotomy and liver exposure. Total hepatic blood flow (THBF) was measured by the Transonic Medical Flowmeter system. NIRS probes were placed on the liver surface to continuously record changes in hepatic tissue oxyhemoglobin (HbO2), deoxyhemoglobin (Hb), and the reduction-oxidation state of cytochrome oxidase (Cyt Ox). Reduction of hepatic tissue oxygenation was achieved by hepatic vascular inflow occlusion (n = 6) or reduction of inspired oxygen (FIO2; n = 6). The THBF changes correlated significantly with hepatic HbO2 (r = 0.84; P <.001) and Cyt Ox (r = 0.88; P <.001). With reduction of FIO2, a significant correlation was found between arterial oxygen saturation and hepatic HbO2 and Hb (r = 0.99 and r = -0.99, respectively; P <.0001). NIRS measurement of liver parenchymal oxygenation correlates well with changes in liver blood flow and arterial oxygenation.

Prolonged continuous or intermittent vascular inflow occlusion during hemihepatectomy in pigs.

To assess ischemia and reperfusion (I/R) injury in a hemihepatectomy model in pigs after prolonged continuous or intermittent vascular inflow occlusion in the liver. Massive intraoperative blood loss during liver resections can be prevented by temporary vascular inflow occlusion, consequently leading to ischemia and reperfusion injury in the remnant liver. Previously, in a pig liver resection model in which only limited I/R injury was induced during brief (90 min) vascular inflow occlusion, the authors demonstrated reduced I/R injury after continuous (CNT) occlusion, compared to intermittent (INT). This liver resection study on pigs was undertaken to assess I/R injury after prolonged (120 min) CNT or INT occlusion. In pigs (37.0 +/- 1.5 kg), liver ischemia during 2 hours was CNT (n = 6) or INT (n = 6) (eight subsequent periods of 12 min ischemia and 3 min recirculation), followed by 6 hours of reperfusion. A left hemihepatectomy (45.5% +/- 1.4%) was performed within the first 12 minutes of ischemia. No hepatic pedicle clamping or liver resection was performed in control experiments (n = 6). Microvascular damage was assessed by hyaluronic acid (HA) uptake capacity of the liver (parameter of early sinusoidal endothelial cell damage) and restoration of intrahepatic tissue pO2 during reperfusion. Hepatocellular damage was tested by plasma concentrations of aspartate aminotransferase (AST), alanine aminotransferase, and lactate dehydrogenase (LDH). Hyaluronic acid uptake after 6 hours of reperfusion, compared to preischemic uptake, was unaltered in the control group, but was significantly reduced in both resection groups. However, more HA was taken up after INT occlusion, compared to CNT (60.4% +/- 5.6% and 39.5% +/- 3.7%, respectively; ANOVA: p = 0.001). Intrahepatic tissue pO2 distribution after 6 hours of reperfusion more closely returned to preischemic configuration in the INT group than in the CNT group, indicating reduced microcirculatory disturbances after INT occlusion. Release of AST and LDH after 6 hours of reperfusion was significantly increased in both CNT and INT groups. Lower AST levels, however, were found after INT occlusion than after CNT occlusion (267.0 +/- 74.7 U/l and 603.3 +/- 132.4 U/l, respectively; p = 0.06). Intermittent hepatic vascular inflow occlusion during prolonged liver ischemia in pigs resulted in less microcirculatory and hepatocellular injury, compared to continuous occlusion. Intermittent clamping is preferable when prolonged periods of vascular inflow occlusion are applied during liver resections.