Hepatic vascular occlusion: which technique?

Inter-patient heterogeneity in the hepatic ischemia-reperfusion injury transcriptome: Implications for research and diagnostics

Cellular responses induced by surgical procedure or ischemia-reperfusion injury (IRI) may severely alter transcriptome profiles and complicate molecular diagnostics. To investigate this effect, we characterized such pre-analytical effects in 143 non-malignant liver samples obtained from 30 patients at different time points of ischemia during surgery from two individual cohorts treated either with the Pringle manoeuvre or total vascular exclusion. Transcriptomics profiles were analyzed by Affymetrix microarrays and expression of selected mRNAs was validated by RT-PCR. We found 179 mutually deregulated genes which point to elevated cytokine signaling with NFκB as a dominant pathway in ischemia responses. In contrast to ischemia, reperfusion induced pro-apoptotic and pro-inflammatory cascades involving TNF, NFκB and MAPK pathways. FOS and JUN were down-regulated in steatosis compared to their up-regulation in normal livers. Surprisingly, molecular signatures of underlying primary and secondary cancers were present in non-tumor tissue. The reported inter-patient variability might reflect differences in individual stress responses and impact of underlying disease conditions. Furthermore, we provide a set of 230 pre-analytically highly robust genes identified from histologically normal livers (<2% covariation across both cohorts) that might serve as reference genes and could be particularly suited for future diagnostic applications.

Hepatocellular Carcinoma: Surgical Management and Evolving Therapies

Hepatocellular carcinoma (HCC) is the fifth most common cancer in men and the eighth most common cancer in women worldwide. It is also the second leading cause of cancer death worldwide, with 780,000 deaths in 2018. Seventy-two percent of HCC cases occur in Asia, 10% in Europe, 8% in Africa, 5% in North America, and 5% in Latin America (Singal et al. in J Hepatol 72(2):250-261, 2020 [1]).

The effect of the number of hepatic inflow occlusion times on the prognosis of ruptured hepatocellular carcinoma patients after hepatectomy

Background and aim

It has been previously reported that inflow occlusion does not affect postoperative outcomes in hepatocellular carcinoma patients. However, for patients with ruptured hepatocellular carcinoma(rHCC), the effect of hepatic inflow occlusion and the number of occlusion times on the prognosis is unknown.

Methods

203 patients with ruptured hepatocellular carcinoma were enrolled in this study. They were first divided into the non-hepatic inflow occlusion (non-HIO) group and the hepatic inflow occlusion (HIO) group. The Kaplan–Meier method was used to compare the recurrence-free survival and overall survival between the two groups. Patients in the HIO group were further divided into one-time HIO and two times HIO groups. KM method was also used to compare the two groups. Finally, independent risk factors affecting RFS and OS were determined by multivariate Cox regression analysis.

Result

In the non-HIO group, 1-,3- and 5-year OS rates were 67.0%, 41.0%, and 22.0%respectively, and RFS rates were 45.0%, 31.0%, and 20.0% respectively; In the one-HIO group, the 1-,3-, and 5-year OS rates were 55.1%, 32.1%, and 19.2% respectively, and RFS rates were 33.3%, 16.7%, and 7.7% respectively; In the two-HIO group, 1-,3-, and 5-year OS rates were 24.0%, 0.0%, and 0.0% respectively, and RFS rates were 8.0%, 0.0%, and 0.0% respectively. By Cox regression analysis, HIO was an independent risk factor for a poor prognosis in rHCC patients.

Conclusion

One time hepatic inflow occlusion did not affect postoperative OS, but negatively affected the RFS of rHCC patients; two times hepatic inflow occlusion negatively affected the postoperative OS and RFS in patients with rHCC.

The hepatoprotective effect of silibinin after hepatic ischemia/reperfusion in a rat model is confirmed by immunohistochemistry and qRT-PCR

OBJECTIVES

We investigated the positive effect of silibinin after IV administration as silibinin-hydroxypropyl-β-cyclodextrin lyophilized product, by measuring gene expression and liver tissue protein levels of tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, matrix metalloproteinases matrix metalloproteinases and tissue inhibitor of matrix metalloproteinases-2.

METHODS

63 Wistar rats of age 13.24±4.40 weeks underwent ischemia/reperfusion (I/R) injury of the liver. The animals were randomized into three groups: Sham (S; n = 7); Control (C; n-28); silibinin (Si; n-28). The C and Si groups underwent 45 min ischemia. Si received silibinin-hydroxypropyl-β-cyclodextrin intravenously immediately before reperfusion at a dose of 5 mg/kg. Both groups were further divided into 4 subgroups, based on euthanasia time (i.e., 60, 120, 180 and 240 min).

KEY FINDINGS

qRT-PCR results confirmed the statistically significant reduction of the expression of the pro-inflammatory factors at 240 min after I/R injury (tumor necrosis factor-α: P < 0.05; MCR1: P < 0.05) and matrix metalloproteinases (matrix metalloproteinases 2: P < 0.05; matrix metalloproteinases 3: P < 0.05) and the increase of tissue inhibitor of matrix metalloproteinases-2 in liver tissue in the Si group. Moreover, results of immunohistochemistry levels confirmed that at 240 min pro-inflammatory factors (tumor necrosis factor-α: P < 0.05; MCR1: P < 0.05) and matrix metalloproteinases ( matrix metalloproteinases 2: P < 0.05; matrix metalloproteinases 3: P < 0.05) had a statistically significantly lower expression in the Si group while tissue inhibitor of matrix metalloproteinases-2 had a higher expression.

CONCLUSIONS

Silibinin may have a beneficial effect on the protection of the liver.

Long-Term Effects of Pedicle Clamping during Major Hepatectomy for Colorectal Liver Metastases

The use of the Pringle maneuver (PM) varies widely among surgical departments. Its use depends on the operator and type of liver resection. The aim of this study was to determine the impact of the PM on patient outcomes when undergoing major liver resections. This retrospective study comprised 179 colorectal liver metastasis patients from two liver centers from Leeds and Warsaw. Only right or right extended hepatectomies with negative oncological margins were included. The primary outcome measure was the 5-year overall survival (OS). The PM was applied during 60 (33.5%) major hepatectomies included in the study and was associated with a higher peak 3-day postoperative bilirubin concentration (p = 0.002), yet not with the peak 3-day alanine aminotransferase activity (p = 0.415). The 5-year OS after liver resections with the PM and without the PM were 55.0% and 33.4%, respectively (p = 0.019). Following stratification by the Tumor Burden Score, after resections with the use of the PM, superior survival was particularly found in the subgroup of patients at intermediate risk of recurrence (p = 0.004). However, the use of the PM had no significant effect on the 5-year overall survival following adjustment for the confounding effect of the carcinoembryonic antigen concentration (p = 0.265). The use of the PM had no negative effects on the long-term outcomes in patients undergoing major, oncologically radical liver resections for colorectal metastases.

Inhibition of Drp1 SUMOylation by ALR protects the liver from ischemia-reperfusion injury

Hepatic ischemic reperfusion injury (IRI) is a common complication of liver surgery. Although an imbalance between mitochondrial fission and fusion has been identified as the cause of IRI, the detailed mechanism remains unclear. Augmenter of liver regeneration (ALR) was reported to prevent mitochondrial fission by inhibiting dynamin-related protein 1 (Drp1) phosphorylation, contributing partially to its liver protection. Apart from phosphorylation, Drp1 activity is also regulated by small ubiquitin-like modification (SUMOylation), which accelerates mitochondrial fission. This study aimed to investigate whether ALR-mediated protection from hepatic IRI might be associated with an effect on Drp1 SUMOylation. Liver tissues were harvested from both humans and from heterozygous ALR knockout mice, which underwent IRI. The SUMOylation and phosphorylation of Drp1 and their modulation by ALR were investigated. Hepatic Drp1 SUMOylation was significantly increased in human transplanted livers and IRI-livers of mice. ALR-transfection significantly decreased Drp1 SUMOylation, attenuated the IRI-induced mitochondrial fission and preserved mitochondrial stability and function. This study showed that the binding of transcription factor Yin Yang-1 (YY1) to its downstream target gene UBA2, a subunit of SUMO-E1 enzyme heterodimer, was critical to control Drp1 SUMOylation. By interacting with YY1, ALR inhibits its nuclear import and dramatically decreases the transcriptional level of UBA2. Consequently, mitochondrial fission was significantly reduced, and mitochondrial function was maintained. This study showed that the regulation of Drp1 SUMOylation by ALR protects mitochondria from fission, rescuing hepatocytes from IRI-induced apoptosis. These new findings provide a potential target for clinical intervention to reduce the effects of IRI during hepatic surgery.

Complex liver resection under hepatic vascular exclusion and hypothermic perfusion with versus without veno-venous bypass: a comparative study

BACKGROUND

While hypothermic liver perfusion has been shown to improve parenchymal tolerance to complex resections in patients requiring prolonged hepatic vascular exclusion (HVE), the benefit of associated veno-venous bypass (VVB) in this setting remains poorly evaluated.

METHODS

All patients undergoing liver resection requiring HVE and hypothermic liver perfusion for at least 55 min between 2006 and 2017 were retrospectively reviewed. Perioperative outcomes were compared between patients with (VVB+) or without VVB (VVB-).

RESULTS

Twenty-seven patients were analyzed, including 13 VVB+ and 14 VVB-. Median HVE duration was similar in VVB+ and VVB- patients (96 vs. 75 min, respectively). VVB+patients had longer operative time (460 vs. 375 min, p = 0.023) but less blood loss (p = 0.010). Five (19%) patients died postoperatively from liver failure or sepsis, without difference between groups. Postoperative major morbidity rate was similar between VVB+ and VVB- patients (30% vs. 50%, respectively) such as rates of liver failure, haemorrhage, renal insufficiency and sepsis, but VVB- patients experienced more respiratory complications (64% vs. 15%, p = 0.012).

CONCLUSION

During liver resection under HVE and hypothermic liver perfusion, use of VVB allows for reducing blood loss and postoperative respiratory complications. VVB should be recommended in case of liver resection with prolonged HVE.

Accuracy of estimated total liver volume formulas before liver resection

BACKGROUND

Future remnant liver volume is used to predict the risk for liver failure in patients who will undergo major liver resection. Formulas to estimate total liver volume based on biometric data are widely used to calculate future remnant liver volume; however, it remains unclear which formula is most accurate. This study evaluated published estimate total liver volume formulas to determine which formula best predicts the actual future remnant liver volume based on measurements in a large number of patients who underwent associating liver partition and portal vein ligation for staged hepatectomy surgery.

METHODS

All patients with complete liver volume data in the associating liver partition and portal vein ligation for staged hepatectomy registry were included in this study. Estimate total liver volume and estimated future remnant liver volume were calculated for 16 published formulas. The median over- or underestimation compared with actual measured volumes were determined for estimate total liver volume and future remnant liver volume. The proportion of patients with an under- or overestimated future remnant liver volume for each formula were compared with each other using a 25% cut-off for each formula.

RESULTS

Among 529 studied patients, the formulas ranged from a 19% underestimation to a 63% overestimation of estimate total liver volume. Estimation of future remnant liver volume lead to a 10% underestimation to a 5% overestimation among the formulas. Of all studied formulas, the Vauthey1 formula was the most accurate, generating underestimation of future remnant liver volume in 20% and overestimation of future remnant liver volume in 6% of patients.

CONCLUSION

Validation of 16 published total liver volume formulas in a multicenter international cohort of 529 patients that underwent staged hepatectomy revealed that the Vauthey formula (estimate total liver volume = 18.51 × body weight + 191.8) provides the most accurate prediction of the actual future remnant liver volume.

Simultaneous hepatic and portal vein ligation induces rapid liver hypertrophy: A study in pigs

BACKGROUND

Liver hypertrophy induced by partial portal vein occlusion (PVL) is accelerated by adding simultaneous parenchymal transection ("ALPPS procedure"). This preclinical experimental study in pigs tests the hypothesis that simultaneous ligation of portal and hepatic veins of the liver also accelerates regeneration by abrogation of porto-portal collaterals without need for operative transection.

METHODS

A pig model of portal vein occlusion was compared with the novel model of simultaneous portal and hepatic vein occlusion, where major hepatic veins draining the portal vein-deprived lobe were identified with intraoperative ultrasonography and ligated using pledgeted transparenchymal sutures. Kinetic growth was compared, and the portal vein system was then studied after 7 days using epoxy casts of the portal circulation. Portal vein flow and portal pressure were measured, and Ki-67 staining was used to evaluate the proliferative response.

RESULTS

Pigs were randomly assigned to portal vein occlusion (n = 8) or simultaneous portal and hepatic vein occlusion (n = 6). Simultaneous portal and hepatic vein occlusion was well tolerated and led to mild cytolysis, with no necrosis in the outflow vein-deprived liver sectors. The portal vein-supplied sector increased by 90 ± 22% (mean ± standard deviation) after simultaneous portal and hepatic vein occlusion compared with 29 ± 18% after PVL (P < .001). Collaterals to the deportalized liver developed after 7 days in both procedures but were markedly reduced in simultaneous portal and hepatic vein occlusion. Ki-67 staining at 7 days was comparable.

CONCLUSION

This study in pigs found that simultaneous portal and hepatic vein occlusion led to rapid hypertrophy without necrosis of the deportalized liver. The findings suggest that the use of simultaneous portal and hepatic vein occlusion accelerates liver hypertrophy for extended liver resections and should be evaluated further.

A Systematic Review and Meta-Analysis Comparing Liver Resection with the Rf-Based Device Habib™-4X with the Clamp-Crush Technique

Liver cancer is the sixth most common cancer and third most common cause of cancer-related mortality. Presently, indications for liver resections for liver cancers are widening, but the response is varied owing to the multitude of factors including excess intraoperative bleeding, increased blood transfusion requirement, post-hepatectomy liver failure and morbidity. The advent of the radiofrequency energy-based bipolar device Habib™-4X has made bloodless hepatic resection possible. The radiofrequency-generated coagulative necrosis on normal liver parenchyma provides a firm underpinning for the bloodless liver resection. This meta-analysis was undertaken to analyse the available data on the clinical effectiveness or outcomes of liver resection with Habib™-4X in comparison to the clamp-crush technique. The RF-assisted device Habib™-4X is considered a safe and feasible modality for liver resection compared to the clamp-crush technique owing to the multitude of benefits and mounting clinical evidence supporting its role as a superior liver resection device. The most intriguing advantage of the RF-device is its ability to induce systemic and local immunomodulatory changes that further expand the boundaries of survival outcomes following liver resection.

Surgical Management of Solid Organ Injuries

Surgery used to be the treatment of choice in patients with solid organ injuries. This has changed over the past 2 decades secondary to advances in noninvasive diagnostic techniques, increased availability of less invasive procedures, and a better understanding of the natural history of solid organ injuries. Now, nonoperative management (NOM) has become the initial management strategy used for most solid organ injuries. Even though NOM has become the standard of care in patients with solid organ injuries in most trauma centers, surgeons should not hesitate to operate on a patient to control life-threatening hemorrhage.

Modified hanging manoeuvre facilitates inferior vena cava resection and reconstruction during extended right hepatectomy: A technical case report

Liver resections are safe when performed by specialized hepatobiliary teams. However, complex liver resections are accompanied by significant perioperative risk and they may require modifications of the conventional surgical techniques. We herein report the case of a 54-year-old male patient who underwent an extended right liver resection with en bloc resection and reconstruction of the inferior vena cava. For this complex resection, a modification of the standard operative technique was required. A modified hanging manoeuvre was performed using two 19Fr nasogastric tubes outside the traditional avascular plane to facilitate resection. This modification of the hanging manoeuvre was proven to be feasible and safe, and it is recommended for inclusion in the armamentarium of hepatobiliary surgeons when complex resections are required.

Continuous Pringle maneuver does not affect outcomes of patients with hepatocellular carcinoma after curative resection

AIM

To investigate whether the use of continuous Pringle maneuver (PM) adversely impacts the outcome of patients with hepatocellular carcinoma (HCC).

METHODS

From January 1989 to January 2011, 586 HCC patients who underwent curative resection in Peking Union Medical College Hospital were identified from the database. Continuous PM was performed in 290 patients (PM group), including 163 patients with a hepatic inflow occlusion time of <15 min (PM-1 group) and 127 with 15-30 min (PM-2 group). An additional 296 patients underwent partial hepatectomy without inflow occlusion (occlusion-free, OF group).

RESULTS

The PM group showed less estimated blood loss during hepatectomy than the OF group (P = 0.005) and the two groups experienced similar incidence of perioperative complications. There were no significant differences in either overall survival or disease-free survival (DFS) between the PM and OF groups (P = 0.117 and 0.291, respectively), and between the PM-1 and PM-2 groups (P = 0.344 and 0.103, respectively). Hepatic inflow occlusion and occlusion time were not independent risk factors for OS or DFS.

CONCLUSIONS

Continuous PM effectively reduces intraoperative bleeding and does not adversely impact the outcomes of HCC patients. It remains a valuable tool in hepatic resection, even difficult, complicated resections requiring prolonged clamping times.

Acute renal injury after partial hepatectomy

Currently, partial hepatectomy is the treatment of choice for a wide variety of liver and biliary conditions. Among the possible complications of partial hepatectomy, acute kidney injury (AKI) should be considered as an important cause of increased morbidity and postoperative mortality. Difficulties in the data analysis related to postoperative AKI after liver resections are mainly due to the multiplicity of factors to be considered in the surgical patients, moreover, there is no consensus of the exact definition of AKI after liver resection in the literature, which hampers comparison and analysis of the scarce data published on the subject. Despite this multiplicity of risk factors for postoperative AKI after partial hepatectomy, there are main factors that clearly contribute to its occurrence. First factor relates to large blood losses with renal hypoperfusion during the operation, second factor relates to the occurrence of post-hepatectomy liver failure with consequent distributive circulatory changes and hepatorenal syndrome. Eventually, patients can have more than one factor contributing to post-operative AKI, and frequently these combinations of acute insults can be aggravated by sepsis or exposure to nephrotoxic drugs.

Short-term Total Hepatic Vascular Exclusion in Difficult Caudate Lobe Dissection in Living-donor Liver Transplantation Recipients

BACKGROUND

Recipient hepatectomy can be complicated by severe bleeding during caudate lobe dissection in living-donor liver transplantation (LDLT), especially when the inferior vena cava is encased or with dense adhesions from prior interventions. Total hepatic vascular exclusion (TVE) including total hepatic inflow (Pringle maneuver) and occlusion of supra- and infra-hepatic inferior vena cava during the partial hepatectomy has been studied well, but it has not been mentioned regarding recipient hepatectomy in LDLT. The aim of this study is to evaluate hemodynamic impact and surgical outcome by using the technique of TVE in LDLT.

METHODS

From April 2010 to June 2010, 30 consecutive LDLT recipients at Kaohsiung Chang Gung Memorial Hospital with TVE (TVE group, n = 14) or without TVE (non-TVE group, n = 16) for the caudate lobe dissection were analyzed retrospectively.

RESULTS

The TVE group had a mean decrease in systolic blood pressure and cardiac index of 21% and 41% during caudate dissection in recipient hepatectomy, respectively. The TVE group had shorter time for caudate mobilization and less blood loss compared with the non-TVE group (3904 mL vs. 5650 mL, P = .461). Two patients in the non-TVE group were shifted to TVE as a salvage procedure to control bleeding. Three patients in the non-TVE group underwent relaparotomy for homeostasis.

CONCLUSIONS

Short-term TVE is a technically feasible procedure and should be considered during recipient hepatectomy with difficult caudate lobe dissection in LDLT to create a bloodless surgical field. Most patients tolerated the TVE without hemodynamic impact under anesthetic management.

Hepatic ischemia reperfusion injury: A systematic review of literature and the role of current drugs and biomarkers

Hepatic ischemia reperfusion injury (IRI) is not only a pathophysiological process involving the liver, but also a complex systemic process affecting multiple tissues and organs. Hepatic IRI can seriously impair liver function, even producing irreversible damage, which causes a cascade of multiple organ dysfunction. Many factors, including anaerobic metabolism, mitochondrial damage, oxidative stress and secretion of ROS, intracellular Ca(2+) overload, cytokines and chemokines produced by KCs and neutrophils, and NO, are involved in the regulation of hepatic IRI processes. Matrix Metalloproteinases (MMPs) can be an important mediator of early leukocyte recruitment and target in acute and chronic liver injury associated to ischemia. MMPs and neutrophil gelatinase-associated lipocalin (NGAL) could be used as markers of I-R injury severity stages. This review explores the relationship between factors and inflammatory pathways that characterize hepatic IRI, MMPs and current pharmacological approaches to this disease.

Combined ultrasonic aspiration and saline-linked radiofrequency precoagulation: a step toward bloodless liver resection without the need of liver inflow occlusion: analysis of 313 consecutive patients

BACKGROUND

Hemorrhage is undoubtedly one of the main factors contributing to morbidity and mortality in liver resections. Vascular occlusion techniques are effective in controlling intraoperative bleeding, but they cause liver damage due to ischemia. We evaluated the effectiveness and safety of using a combined technique for hepatic parenchymal transection without liver inflow occlusion.

METHODS

Three hundred and thirteen consecutive patients who underwent liver resection in four hepato-pancreato-biliary units. Hepatic parenchymal transection was carried out using a combined technique of saline-linked radiofrequency precoagulation and ultrasonic aspiration without liver inflow occlusion.

RESULTS

During the study period 114 minor and 199 major hepatic resections were performed. The mean amount of intraoperative blood loss was 377 ml (SD 335 ml, range 50 to 2,400 ml) and the blood transfusion rate was 10.5%. The median amount of blood loss during parenchymal transection and parenchymal transection time was 222 ml (SD 224 ml, range 40 to 2,100 ml) and 61 minutes (range 12 to 150 minutes) respectively. There were two postoperative deaths (0.6%). Complications occurred in 84 patients (26.8%) and most complications were minor.

CONCLUSIONS

Combined technique of saline-linked radiofrequency ablation and ultrasonic aspiration for liver resection is a safe method for both major and minor liver resections. The method is associated with decreased blood loss, reduced postoperative morbidity, and minimal mortality rates. We believe that this combined technique is comparable to other techniques and should be considered as an alternative.

Vascular anatomy of canine hepatic venous system: a basis for liver surgery

Detailed knowledge of the vascular anatomy is important for improving surgical approaches to the liver. Twelve canine livers were skeletonized to describe the anatomy of their portal and hepatic veins in details. Our data suggest that the liver can be divided into two sections, three divisions, seven lobes and two to four sub-lobes. This differs from the classic division into four lobes, four sub-lobes and two processes. The right section was perfused by the right portal branch and drained by independent hepatic veins, while most of the left section, perfused by the left portal branch, was drained by the main hepatic vein deriving from the middle and the left hepatic vein confluence. Part of the right medial lobe, and in some cases the papillary process of the caudate lobe, drained directly into the caudal vena cava. A proper right hepatic vein draining blood from more than one lobe was never observed. Portal connections between the quadrate and the left medial lobe were frequently recorded. Two sub-lobes with different portal blood supply and venous drainage could be identified in the right lateral (33.3% of cases) and the left lateral (100% of cases) lobes. From our results, the classic nomenclature of the liver lobes does not reflect their vascularization. Based on similarities between canine lobes and human segments, a new nomenclature is possible and may be less confounding in surgical settings.

Transhepatic anterior approach to the inferior vena cava in large retroperitoneal tumors resected en bloc with the right liver lobe

BACKGROUND

The operative approach to large retrohepatic tumors can be challenging because of the difficulty in exposing the inferior vena cava (IVC) and controlling bleeding. The anterior approach to the IVC associated with the hanging maneuver for liver transection, originally described in large hepatic tumors, may also facilitate removal of large masses set behind the liver.

METHODS

A prospective cohort of 10 patients with large retrohepatic tumors involving the IVC was selected according to restrictive criteria (ie, single low-grade tumor, sufficient liver remnant, normal hepatic function, absence of cholestasis, and symptoms secondary to lower vena cava obstruction). In all cases, the anterior approach and the hanging maneuver were applied intentionally to expose the IVC without any liver mobilization. Depending on tumor invasiveness, either IVC-preserving (n = 7) or IVC-removing (n = 3) strategies were applied. Our aim was to assess the safety of the technique and the possible benefits for patient outcome.

RESULTS

The cohort represented less than 1% of a series of 1,168 major hepatectomies performed in our unit between 2005 and 2011. The median age of the patients was 58; adrenal tumors and retroperitoneal sarcomas accounted for 70% of the series. Total vascular liver exclusion was necessary in 3 patients. Median operative time was 420 min. R0 resection was obtained in all cases, with no mortality and 40% overall morbidity. Overall survival was 83% at 5 years.

CONCLUSION

The transhepatic, anterior approach to the IVC is a safe procedure that improves vascular control, facilitates vein repair or reconstruction, and allows potentially curative resection of large retrohepatic tumors. This approach should be the preferred choice to be adopted in properly selected patients.

Efficacy and safety of hepatectomy performed with intermittent portal triad clamping with low central venous pressure

Background. This retrospective study was designed to investigate the efficacy and safety of intermittent portal triad clamping (PTC) with low central venous pressure (CVP) in liver resections. Methods. Between January 2007 and August 2013, 115 patients underwent liver resection with intermittent PTC. The patients' data were retrospectively analyzed. Results. There were 58 males and 57 females with a mean age of 55 years (±13.7). Cirrhosis was found in 23 patients. Resections were performed for malignant disease in 62.6% (n = 72) and for benign disease in 37.4% (n = 43). Major hepatectomy was performed in 26 patients (22.4%). Mean liver ischemia period was 27.1 min (±13.9). The mortality rate was 1.7% and the morbidity rate was 22.6%. Cumulative clamping time (t = 3.61, P < 0.001) and operation time (t = 2.38, P < 0.019) were significantly correlated with AST alterations (D-AST). Cumulative clamping time (t = 5.16, P < 0.001) was significantly correlated with D-ALT. Operation time (t = 5.81, P < 0.001) was significantly correlated with D-LDH. Conclusions. Intermittent PTC under low CVP was performed with low morbidity and mortality. Intermittent PTC can be safely applied up to 60 minutes in both normal and impaired livers.

Methods of haemostasis during liver resection--a UK national survey

BACKGROUND

Although haemorrhage is a major cause of morbidity and mortality in liver surgery, there is very little available guidance on its management.

METHODS

The aim of this study was to identify current practice in the UK in this regard. An online survey was created and hepatobiliary (HPB) specialists who were members of a specialist society and others who were known practitioners were invited by e-mail to complete the survey anonymously.

RESULTS

Fifty-one percent responded (n = 36/70), and most of these respondents worked at large HPB centres (>100 liver resections/year; n = 24, 66%). Not all questionnaires were fully completed by the individual surgeons. Thirty-eight percent of the surgeons routinely used Pringle's manoeuvre. Most surgeons used ligation of the inflow vessels (n = 16, 44%) and stapled the outflow vessels (n = 15, 42%). The Cavitron ultrasonic surgical aspirator (CUSA; 54%, 13/24) was preferred for parenchymal transection. The majority routinely used haemostatic adjuncts (n = 22, 62%), whilst 33% (n = 12) used them occasionally. Twenty-three (64%) felt manufactured haemostatic adjuncts played a major role in maintaining haemostasis and 19 preferred fibrin-based products.

CONCLUSION

The Pringle manoeuvre is a popular technique amongst specialist UK liver surgeons and the CUSA is used by nearly half of the surgeons. Despite the absence of definitive evidence for their benefit, manufactured haemostatic adjuncts are still widely used, especially the fibrin-based adjuncts.

Ischemia/reperfusion injury after continuous or intermittent hepatic pedicle clamping in rabbits

BACKGROUND

The control of bleeding in hepatectomy is a challenge for surgeons. The hepatic pedicle clamping is a surgical maneuver that can provide reduction in bleeding, but it provokes a hepatocellular suffering. This, along with reperfusion after the clamping finishes, leads to an injury known as ischemia/reperfusion injury.

AIM

To examine the effects of the ischemia/reperfusion injury on the liver after continuous and intermittent hepatic pedicle clamping in an animal model, using the quantification of apoptosis for evaluation.

METHOD

Twenty New Zealand rabbits were assigned to groups 1 (control), 2 (60 minutes of continuous ischemia) and 3 (60 minutes of intermittent ischemia alternating 12 minutes of ischemia and three minutes of reperfusion). Liver biopsies were collected before ischemia, at its end and after six hours of reperfusion, when the animals were killed. The liver fragments were subjected to histological analysis (paraffinization and hematoxilin-eosin staining) and histochemical (Tunel reaction). Microscope fields of view were scanned for characterization and quantification of apoptosis.

RESULTS

Ischemia led to an increased apoptotic index in both experimental groups in comparison to controls, but similarly between them. After the reperfusion, the indexes returned to baseline values.

CONCLUSION

Clamping of the hepatic pedicle, either continuous or intermittent, induces apoptosis in liver cells in a similar way.

Bleeding in Hepatic Surgery: Sorting through Methods to Prevent It

Liver resections are demanding operations which can have life threatening complications although they are performed by experienced liver surgeons. The parameter “Blood Loss” has a central role in liver surgery, and different strategies to minimize it are a key to improve results. Moreover, recently, new technologies are applied in the field of liver surgery, having one goal: safer and easier liver operations. The aim of this paper is to review the different principal solutions to the problem of blood loss in hepatic surgery, focusing on technical aspects of new devices.

Perioperative analysis of laparoscopic liver resection with different methods of hepatic inflow occlusion

BACKGROUND

During liver resection, bleeding remains the most important challenge. A reduction in blood loss and avoiding the need for a blood transfusion are important objectives for liver surgeons today. The authors compared the intra- and postoperative course of patients undergoing laparoscopic liver resections under intermittent total pedicle occlusion (IPO), hemihepatic vascular occlusion (HVO), and selective vascular occlusion (SVO).

SUBJECTS AND METHODS

Retrospective analysis was conducted of patient data from 41 cases of laparoscopic liver resection in three groups of patients under different occlusion methods, including 15 cases of IPO, 15 cases of HVO, and 11 cases of SVO. The advantages and disadvantages of the various methods were compared, as well as blood loss, operation time, changes in postoperative liver function, and complications.

RESULTS

There was no operative death in any of the 41 patients. Generally, there was no significant difference among the three groups in blood loss, clamping time, or operative time. After the operation, the effect on liver function for the HVO and SVO groups was significantly less severe than that for the IPO group (P<.05). The incidence of postoperative complications was mainly related to IPO and the larger amount of bleeding.

CONCLUSIONS

Both HVO and SVO are feasible in laparoscopic hepatectomy and have the advantage of reducing liver remnant ischemia injury and modality rate over IPO. HVO is easy to do for left lateral lobe or resection of the left half of the liver. SVO is suitable for right lobe resection.

Techniques of hepatic resection

Liver resections are high risk procedures performed by experienced surgeons. The role of liver resection in malignant disease has changed over the last 100 years with great improvement in morbidity, mortality and long term survival. New understanding in liver anatomy, improved perioperative care, anesthesia techniques, and technological advances has improved this aspect of patient care. With improved techniques, patients previously considered unresectable have an opportunity to undergo curative surgery. This review article describes the various approaches and techniques for liver resection. The relevant anatomy and terminology of hepatic resections is discussed, as well as the role of anatomic vs. nonanatomic resection. Methods of vascular control are examined and the multiple strategies of parenchymal transection are compared, as well as minimally-invasive techniques. Finally, a brief review of the authors' practice in terms of surgical technique is offered.

Randomized clinical trial of open hepatectomy with or without intermittent Pringle manoeuvre

BACKGROUND

The intermittent Pringle manoeuvre (IPM) is commonly applied during liver resection. Few randomized trials have addressed its effectiveness in reducing blood loss and the results have been conflicting. The present study investigated the hypothesis that IPM could reduce blood loss during liver resection by 50 per cent.

METHODS

Between May 2008 and April 2011, patients who underwent elective open hepatectomy were randomized into an IPM or no Pringle manoeuvre (NPM) group and stratified according to the presence or absence of cirrhosis. Data on demographics, type of hepatectomy, operative blood loss, duration of operation, mortality, morbidity and postoperative liver function were recorded and analysed. The primary endpoint was operative blood loss.

RESULTS

There were 63 patients in each group. Median (range) operative blood loss was 370 (50-3600) ml in the IPM group versus 335 (40-3160) ml in the NPM group (P = 1·000). There were no differences in blood loss in different phases of the operation, blood loss per area of liver transected or blood transfusion rate, nor in total duration of operation or liver transection time. Postoperative serum alanine aminotransferase levels were higher in the IPM group (P < 0·001). There were more postoperative complications in the IPM group (41 versus 24 per cent; P = 0·036).

CONCLUSION

The IPM did not reduce blood loss, but was associated with raised levels of postoperative liver parenchymal enzymes and more complications.

REGISTRATION NUMBER

NCT00730743 (http://www.clinicaltrials.gov).

Anesthetic Considerations in Hepatectomies under Hepatic Vascular Control

Background. Hazards of liver surgery have been attenuated by the evolution in methods of hepatic vascular control and the anesthetic management. In this paper, the anesthetic considerations during hepatic vascular occlusion techniques were reviewed. Methods. A Medline literature search using the terms "anesthetic," "anesthesia," "liver," "hepatectomy," "inflow," "outflow occlusion," "Pringle," "hemodynamic," "air embolism," "blood loss," "transfusion," "ischemia-reperfusion," "preconditioning," was performed. Results. Task-orientated anesthetic management, according to the performed method of hepatic vascular occlusion, ameliorates the surgical outcome and improves the morbidity and mortality rates, following liver surgery. Conclusions. Hepatic vascular occlusion techniques share common anesthetic considerations in terms of preoperative assessment, monitoring, induction, and maintenance of anesthesia. On the other hand, the hemodynamic management, the prevention of vascular air embolism, blood transfusion, and liver injury are plausible when the anesthetic plan is scheduled according to the method of hepatic vascular occlusion performed.

Randomized clinical trial comparing infrahepatic inferior vena cava clamping with low central venous pressure in complex liver resections involving the Pringle manoeuvre

BACKGROUND

Control of bleeding remains key to successful hepatic resection. The present randomized clinical trial compared infrahepatic inferior vena cava (IVC) clamping with low central venous pressure (CVP) during complex hepatectomy using portal triad clamping (PTC).

METHODS

Consecutive patients undergoing complex hepatectomy were allocated randomly to PTC combined with infrahepatic IVC clamping or to PTC with low CVP. Primary outcome was blood loss during parenchymal transection. Secondary outcomes were intraoperative surgical and haemodynamic parameters, postoperative recovery of liver and renal function, postoperative morbidity and mortality, and duration of hospital stay.

RESULTS

Between January 2008 and September 2010, 192 patients were randomized. Compared with low CVP, infrahepatic IVC clamping significantly decreased blood loss during parenchymal transection (mean(s.e.m.) 243(158) versus 372(197) ml; P < 0·001), was associated with faster recovery of liver function, and caused less impairment in renal function and fewer haemodynamic changes. The degree of cirrhosis correlated positively with CVP (R(2) = 0·963, P = 0·019) and with infrahepatic IVC pressure (R(2) = 0·950, P = 0·025). For patients with moderate or severe cirrhosis, infrahepatic IVC clamping was more efficacious in controlling blood loss during parenchymal transection (mean(s.e.m.) 2·9(1·8) versus 6·1(2·4) ml/cm(2); P < 0·001).

CONCLUSION

PTC combined with infrahepatic IVC clamping is more efficacious in controlling bleeding during complex hepatectomy than PTC with low CVP, especially in patients with moderate to severe cirrhosis.

REGISTRATION NUMBER

NCT01355887 (http://www.clinicaltrials.gov).

Treatment of the liver cross section following hepatectomy

The incidence of complications after hepatectomy has been considerably reduced over the last 20 years. Better knowledge of liver anatomy and liver regeneration, and methods preventing bleeding during surgery have resulted in morbidity rates below 20% and mortality rates less than 5%. The treatment of the liver cross section remains controversial. Experimental studies have reported convincing biological effects of fibrin sealants or compresses when applied on the liver to decrease hemorrhagic or biliary complications. However, clinical studies are very heterogeneous, providing conflicting results compromising recommendations for routine use.

Hepatic resection nomenclature and techniques

Nomenclature describing liver anatomy and liver resection has been standardized with the Brisbane 2000 terminology. When performing liver resection, blood loss should be minimized by using low central venous pressure (CVP) anesthesia and vascular occlusion as appropriate. There are many options for transection of the liver parenchyma, and although no technique has been shown to be superior to clamp-crushing, hepatic surgeons should be familiar with the techniques available.

Current management of hepatic trauma

With the shift toward nonoperative management, most hepatic injuries are managed nonoperatively. On the other hand, up to two-thirds of high-grade hepatic injuries require laparotomy; these cases are technically difficult and challenging. Damage-control approaches, understanding of liver anatomy, and advances in technology have dramatically changed the approach to hepatic trauma, with improved outcomes. Anatomic or nonanatomic liver resection is required in 2% to 5% of liver injuries. Mortality with liver injury following resection is 9% with current advances.

Dual effect of erythropoietin on liver protection and regeneration after subtotal hepatectomy in rats

The only currently offered curative option for many patients with primary or secondary liver tumors is the resection of hepatic tumors. The aim of this study was to evaluate the role of recombinant human erythropoietin (rhEPO) in liver protection and regeneration after subtotal hepatectomy in rats. Rats undergoing 70% hepatectomy received an intraperitoneal injection of saline (control) or rhEPO (4 U/g) 30 minutes prior to resection. Liver function was assessed by the measurement of the international normalized ratio (INR) levels, and hepatic injury was assessed by serum alanine aminotransferase and aspartate aminotransferase levels. Hepatic apoptosis was assessed by intrahepatic caspase-3 activity and morphological criteria. The regeneration capacity of remnant livers was assessed over 7 days with the regenerated liver/body weight ratio, immunohistochemistry markers of cell proliferation (Ki-67) and angiogenesis (von Willebrand factor), and phosphorylated extracellular signal-regulated kinase signaling. Two and 4 days after subtotal hepatectomy, the regenerated liver/body weight ratio was significantly higher in animals treated with rhEPO versus the control group (P < 0.005). Serum liver enzymes and INR levels on days 2 and 4 post-hepatectomy were significantly lower in animals pretreated with rhEPO in comparison with the control group (P < 0.005). No statistically significant difference was noted in intrahepatic hepatic caspase-3 activity, immunohistochemistry for caspase-3, or a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay between the hepatectomized groups. In the rhEPO-pretreated group, the mitotic index, Ki-67 and von Willebrand factor expression, and extracellular signal-regulated kinase activity were significantly higher on day 2 post-hepatectomy (P < 0.05) in comparison with the control group. In conclusion, rhEPO treatment may offer a unique beneficial dual-function strategy for hepatic protection and regeneration immediately after subtotal hepatectomy in rats.

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 injuries]

The liver is the most commonly injured abdominal organ. Severe hepatic trauma continue to be associated with high mortality. Management of liver injuries has changed significantly over the last two decades. Nonoperative management of hemodynamically stable patients has become the first treatment of choice. In unstable patients immediate control of bleeding is critical. In the management of severe injuries of the liver, particularly for patients who had developed a metabolic insult (hypothermia, coagulopathy, and acidosis), perihepatic packing has emerged as the key to effective damage control (DCS). The surgical aim is control of hemorrhage, preservation of sufficient hepatic function and prevention of secondary complications. Currently available surgical methods include hepatorrhaphy, resectional debridement, anatomical/nonanatomical resection, selective hepatic artery ligation, Pringle maneuver, total vascular exclusion, liver transplatation. This review discusses available diagnostic modalities and the best management options for liver injury, based on literature search and authors experience.

Liver resection under total vascular exclusion with or without preceding Pringle manoeuvre

BACKGROUND

Adequate control of bleeding is crucial during liver resection. This study analysed the safety and efficacy of hepatectomy under total hepatic vascular exclusion (THVE) in patients with tumours encroaching or infiltrating the hepatic veins and/or the inferior vena cava (IVC).

METHODS

All patients undergoing liver resection with THVE between January 2000 and July 2006 were identified from a prospectively collected database containing 2400 patients. Data on patient demographics, surgical procedure and outcome were collected.

RESULTS

A total of 87 patients scheduled for liver resection under THVE were identified, 77 with malignant tumours and ten with benign disease. THVE could not be used in two patients (2 per cent) owing to haemodynamic intolerance during trial clamping. Seventeen patients received simultaneous clamping of the portal triad and vena cava, and 68 had portal triad clamping followed by concomitant portal and vena cava clamping. The mean(s.d.) duration of THVE was 28.3(7.5) and 18.7(5.2) min respectively. Overall postoperative complication and operative mortality rates were 53 and 2 per cent respectively. Mean(s.d.) hospital stay was 16.8(4.7) days.

CONCLUSION

Major hepatic resection for tumours encroaching on the hepatic veins or IVC can be carried out under THVE with reasonable morbidity and mortality.

Randomized clinical trial of efficacy and costs of three dissection devices in liver resection

BACKGROUND

In recent decades a variety of instruments for liver dissection has become available. This randomized controlled trial analysed the efficacy and costs of three different liver dissection devices.

METHODS

Ninety-six patients without cirrhosis undergoing liver resection were randomized to either ultrasonic dissection, waterjet dissection or dissecting sealer (32 in each group). Patients were unaware of the device used. The primary endpoint was dissection speed. Secondary endpoints were intraoperative blood loss, morbidity and mortality, and costs of dissection devices, staplers and haemostatic agents.

RESULTS

Dissection was slower with the dissecting sealer (P = 0.004 versus waterjet dissector). The difference was more pronounced for extended resections (mean(s.e.m.) 1.62(0.36) cm(2)/min versus 3.42(0.53) and 3.63(0.51) cm(2)/min for ultrasonic and water dissectors respectively; P = 0.037). Costs were significantly higher for the dissecting sealer when atypical or segmental resections were performed. Four patients died after extended resections; postoperative complications did not differ between groups.

CONCLUSION

The dissecting sealer is slower than the ultrasonic dissector or water dissector. The three devices are equally safe in terms of blood loss, transfusions and postoperative complications. Ultrasonic and water dissectors might be more favourable economically than the dissecting sealer.

REGISTRATION NUMBER

ISRCTN52294555 (http://www.controlled-trials.com).

Feasibility of liver resection without the use of the routine Pringle manoeuver: an analysis of 248 consecutive cases

BACKGROUND

New instruments and techniques for hepatectomy have been shown to reduce blood loss during liver resection. The present study aims to evaluate the feasibility and result of our techniques of liver resection without routine inflow occlusion (the Pringle manoeuver).

METHODS

The cavitron ultrasonic surgical aspirator (CUSA) and saline-linked radio-frequency dissecting sealer (TissueLink) were used together for open hepatectomy, whereas a bipolar vessel sealing device (Ligasure) and TissueLink were used for laparoscopic hepatectomy. Between June 2003 and May 2007, 248 consecutive cases of liver resection were carried out using the above techniques without the routine Pringle manoeuver. The operative and clinical outcome data were prospectively collected and analysed.

RESULTS

During the study period, a total of 220 cases of open hepatectomy and 28 cases of laparoscopic hepatectomy were performed. The Pringle manoeuver was eventually applied in six patients (2.4%): two for portal vein tumour thrombus extraction and four as a result of heavy bleeding. Median blood loss was 300 ml (20-2700 ml) and the blood transfusion rate was 7.7%. In most of the cases, the liver function tests showed improvement on post-operative day 1 or 2, and the median post-operative hospital stay was 7 days. There were two post-operative deaths (0.8%). Complications occurred in 63 patients (25.4%) and most complications were minor.

CONCLUSIONS

Refined techniques and instruments for liver resection allow hepatectomy to be done safely without using the routine Pringle manoeuver. Most patients had a quick recovery of liver function and were discharged early.

Clamp-crush technique vs. radiofrequency-assisted liver resection for primary and metastatic liver neoplasms

BACKGROUND

Several techniques for liver resection have been developed. We compared radiofrequency-assisted (RF) and clamp-crush (CC) liver resection (LR) in terms of blood loss, operating time and short-term outcomes in primary and metastatic tumour resection.

METHODS

From 2002 to 2007, 196 consecutive patients with primary or metastatic hepatic tumours underwent RF-LR (n= 109; group 1) or CC-LR (n= 87; group 2) in our unit. Primary endpoints were intraoperative blood loss (and blood transfusion requirements) and total operative time. Secondary endpoints included postoperative complications, mortality and intensive care unit (ICU) and hospital stay. Data were collected retrospectively on all patients with primary or secondary liver lesions.

RESULTS

Blood loss was similar (P= 0.09) between the two groups of patients with the exception of high MELD score (>9) cirrhotic patients, in whom blood loss was lower when RF-LR was used (P < 0.001). Total operative time and transection time were shorter in the CC-LR group (P= 0.04 and P= 0.01, respectively), except for high MELD score (>9) cirrhotic patients, in whom total operation and transection times were shorter when RF-LR was used (P= 0.04). Rates of bile leak and abdominal abscess formation were higher after RF-LR (P= 0.04 for both).

CONCLUSIONS

Clamp-crush LR is reliable and results in the same amount of blood loss and a shorter operating time compared with RF-LR. Radiofrequency-assisted LR is a unique, simple and safe method of resection, which may be indicated in cirrhotic patients with high MELD scores.

Clamping techniques and protecting strategies in liver surgery

The use of vascular occlusion during liver resection is still a matter of debate. The aim of this review was to assess the advantages and disadvantages of portal triad occlusion as a protective strategy during elective liver resection and liver transplantation. Newer strategies such as pharmacological preconditioning are also discussed. A systematic literature search was conducted to detect randomized controlled trials assessing the effectiveness and safety of portal triad clamping, ischaemic preconditioning and pharmacological preconditioning during liver surgery. Vascular clamping cannot be systematically recommended. When used, portal triad clamping is associated with a tendency towards reduced blood loss and blood transfusion without having an impact on morbidity. Intermittent clamping appears to be better tolerated than continuous clamping, especially in patients with chronic liver disease. Ischaemic preconditioning before continuous portal triad clamping reduces reperfusion injury after warm ischaemia, particularly in steatotic patients. Ischaemic preconditioning has unclear effects in transplantation and there is currently no evidence to support or refute the use of ischaemic preconditioning in the donor. There are emerging alternative conditioning strategies, including the use of volatile anaesthetics, which may provide new and easily applicable therapeutic options to protect the liver.

The liver hanging manoeuvre

The liver hanging manoeuvre (LHM) facilitates the anterior approach (AA), which is one of the most important innovations in the field of major hepatic resections. The AA confers some definite advantages over the classical approach, in that it provides for: less haemorrhage; less tumoral manipulation and rupture; better haemodynamic stability by avoiding any twisting of the inferior vena cava; reduced ischaemic damage of the liver remnant, and better survival for patients with hepatocellular carcinoma (HCC). The LHM makes the AA easier because it serves as a guide to the correct anatomical transection plane and elevates the deep parenchymal plane. The LHM is a safe technique, in which minor complications have been reported in < or = 7% of patients and >90% feasibility has been demonstrated in experienced centres. Over the years, different variants of the LHM have been developed to facilitate almost all anatomical liver resections. In view of its advantages, feasibility and safety, the LHM should be considered for most anatomical hepatectomies.

Clinical results of N-acetylcysteine after major hepatic surgery: a review

BACKGROUND/PURPOSE

Ischemia/reperfusion injury is thought to play an important role in postoperative liver dysfunction and morbidity following major liver surgery. N-acetylcysteine may be protective by serving as a precursor to glutathione and replenishing intracellular stores, in addition to other mechanisms. The purpose of this review is to summarize the clinical evidence that N-acetylcysteine may reduce liver dysfunction and the postoperative complications following major liver surgery.

METHODS

A PubMed (MEDLINE) search was performed using the search terms "N-acetylcysteine", "Mucomyst", "liver", and "surgery" to identify all relevant articles published in English prior to February 2007.

RESULTS

Seventy-three articles were identified, and of these, there were seven studies that involved human patients undergoing orthotopic liver transplantation (six randomized controlled trials and one retrospective study).

CONCLUSIONS

The evidence that routine use of N-acetylcysteine reduces ischemia/reperfusion injury and prevents complications after major liver surgery is not conclusive. The available studies may have been limited by small sample sizes, and heterogeneous outcome measures prevent conclusions being made across studies and prevent pooling of the data. Further study with more relevant clinical endpoints and larger sample sizes is warranted.

Comparison of two methods of selective hepatic vascular exclusion for liver resection involving the roots of the hepatic veins

BACKGROUND

Selective hepatic vascular exclusion (SHVE) is an effective hepatic vascular exclusion in controlling both inflow and outflow without interruption of caval flow, as it combines Pringle maneuver with extrahepatic selective occlusion of hepatic veins. But SHVE has not been widely used due to difficulty in extrahepatic dissection of hepatic veins. When the tumor is very close to the roots of the hepatic veins, dissecting the posterior wall of the hepatic vein may lead to rupture and massive bleeding of the hepatic vein. With our experience, clamping hepatic veins with Satinsky clamps is a safer and easier occlusion method by which the posterior wall of the hepatic veins does not need to be separated and encircled. In this report, we compared the results of selective hepatic vascular occlusion with tourniquet and Satinsky clamp for major liver resection involving the roots of the hepatic veins.

METHODS

Between January 2003 to June 2006, 180 patients who underwent major liver resection with SHVE were divided into two groups according to different methods of hepatic vascular occlusion: occlusion with tourniquet (tourniquet group, n = 95) and occlusion with Satinsky clamp (Satinsky clamp group, n = 85). In the tourniquet group, the hepatic veins were encircled and occluded with tourniquet. In the Satinsky clamp group, the hepatic veins were not encircled and clamped directly by Satinsky clamp.

RESULTS

Intraoperative and postoperative consequences of the patients were analyzed. The dissecting time for each hepatic vein was significantly shorter in the Satinsky group (6.2 +/- 2.4 min vs 18.3 +/- 6.2 min) than in the tourniquet group. In the tourniquet group, five hepatic veins (one right hepatic vein and four common trunk of left-middle hepatic veins) could not be dissected and encircled because the tumors involved the cava hepatic junction, and another common trunk of the left-middle hepatic vein had a small rupture during the dissection. These six patients then received successful occlusion with Satinsky clamp. There was no difference between the two groups regarding the operation duration, ischemia time, intraoperative blood loss, and postoperative complication rate.

CONCLUSION

Both methods of the hepatic vein occlusion have the same effect on controlling hepatic vein bleeding, but occlusion with Satinsky clamp is safer, easier, and consumes less time in dissecting.

Open hepatic parenchymal transection using ultrasonic dissection and bipolar coagulation

Liver transection is the most challenging part of liver resection due to the risk of massive blood loss which is associated with increased postoperative morbidity and mortality, as well as reduced long-term survival after resection of malignancies. Among the devices used for open parenchyma transection, ultrasonic dissection with bipolar cautery forceps is one of the most widely used technique worldwide. We identified four retrospective comparative studies and three randomized controlled trials dealing with the efficacy of ultrasonic dissector (UD) compared with other techniques including the historical clamp crushing technique. UD is associated with similar blood loss and slower resection time compared with water-jet or clamp crushing technique. However, it seems to be more precise in dissecting vessels. Its use does not impact on morbidity and hospital stay compared with other techniques. From an economic point of view, UD is the most expensive technique and may be a disadvantage for low centre volume. UD with bipolar cautery is one of the safest and the most efficient device for liver transection, even if its superiority over the clamp crushing technique has not been well established. It is considered as a standard technique for liver transection.

Techniques for liver resection: a review

Improvement in surgical outcomes of liver resection has been achieved in the past decade. Among other factors, a gradual change of technology platforms and refinement of surgical techniques have played significant roles. In this review, the various surgical approaches, operative techniques, operative instruments, and adjunctive measures as applied in liver resection are described, along with discussion of the pros and cons of each of these attributes. A brief description of laparoscopic liver resection is also included to address this important and emerging area in liver surgery.

Liver resection for colorectal liver metastasis

At some point in the natural course of colorectal cancer up to 50% of patients will develop metastasis to the liver. Historically only 20% of these patients would have to be deemed resectable, with an intent to cure, at the time of presentation. But with recent improvements in cross-sectional imaging, chemotherapeutic agents and advances in the techniques of surgical resection the emphasis of resection has now changed to 'who is not resectable' as opposed to 'who is resectable'. There are few contraindications to liver resection on the proviso that the patient is fit enough. As a result of this paradigm shift, 5 year survival rates are approaching 60%. Historically liver resection was perceived as a formidable operation but now liver resection for CRLM is safe and specialist centres are reporting mortality rates of less than 1%. This review briefly covers the standard techniques currently employed and some of the recent innovations being developed to improve resectability.