Randomized clinical trial of the effect of a saline-linked radiofrequency coagulator on blood loss during hepatic resection

A randomized controlled trial to compare the efficacy of regenerated and non-regenerated oxidized cellulose gauze for the secondary treatment of local bleeding in patients undergoing hepatic resection

Purpose

Oxidized cellulose is available in many forms, but manufactured using either a regenerated or non-regenerated process. In this study, we evaluated the effects of 2 different hemostatic agents for the treatment of local bleeding in patients undergoing hepatic resection.

Methods

This was a monocentric, parallel-group, randomized, and controlled clinical trial to compare oxidized regenerated cellulose gauze (ORCG) with oxidized non-regenerated cellulose gauze (ONRCG) in patients undergoing hepatectomy. The primary endpoint was the time to hemostasis at the target bleeding site. The secondary endpoints were the postoperative drainage volume on the first 2 days after surgery and the hospital stay.

Results

There was no significant difference between the ORCG and ONRCG groups in time to hemostasis from column analysis (238.8 ± 121.6 seconds vs. 193.7 ± 85.3 seconds, P = 0.068), and there were no differences in the rates of hemostatic success between the 2 groups at 120 seconds (18.4% vs. 24.3%; odds ratio [OR], 0.703; 95% confidence interval [CI], 0.231–2.136) and 300 seconds (71.1% vs. 89.2%; OR, 0.298; 95% CI, 0.085–1.041). However, the ONRCG group was superior to the ORCG group in hemostasis according to the survival analysis (log-rank test, P = 0.044). Moreover, there were also no significant differences between the 2 groups in postoperative drainage volume on the first 2 days (P = 0.436, P = 0.381) and hospital stay (P = 0.537, P = 0.200).

Conclusion

ONRCG was not inferior to ORCG as a hemostatic agent in patients undergoing liver resection.

The use of Thulium-Doped Fiber Laser (TDFL) 1940 nm as an energy device in liver parenchyma resection, a-pilot-study in Indonesia

Introduction

Several modalities are used to improve the outcome of liver resection surgery. Laser-based surgery may become promising option; therefore we aim to report our experience regarding the efficacy and safety of Thulium-Doped Fiber Laser (TDFL) 1940 nm in liver parenchyma resection.

Methods

A cross sectional study in which patients with pre-existing liver pathology during July 2019 and July 2020 were randomly assigned to receive liver resection using TDFL integrated with raman laser emitting at 1940 nm and 1470 nm wavelength. Data on estimated blood loss during liver transection, liver transection speed, morbidity rate, and postoperative variables including complications, length of hospital stay (days), and mortality were analyzed.

Results

A total of 17 consecutive liver resections were performed, among them are 7 major and 11 minor hepatectomies. The Multipulse TM+1470 were used on 8 procedures consisted of 1 major and 7 minor hepatectomies, the mean amount of blood loss during operation and liver transection was 628.13 ± 141.31 mL and 294.63 ± 94.81 ml, respectively. The mean liver transection speed was 1.52 ± 0.27 cm²/min. No biliary leak, post-hepatectomy-liver failure, and mortality were reported.

Conclusion

TDFL provided by Multipulse TM+1470 is an effective and safe tool for liver surgery, providing good hemostasis and allowing for safe and effective exposure of vascular. Further study with larger samples might be needed proved the efficacy and safety of TDFL in liver surgery.

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Despite promising laser device features, the usage in liver surgery is still rare.

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TDFL provides precision transection and good hemostasis.

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Low intraoperative blood loss is observed in TDFL liver surgery.

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No bile leak and post hepatectomy liver failure was observed after TDFL surgery.

A systematic review and network meta-analysis of parenchymal transection techniques during hepatectomy: an appraisal of current randomised controlled trials

BACKGROUND

Major liver resection can lead to significant morbidity and mortality. Blood loss is one of the most important factors predicting a good outcome. Although various transection methods have been reported, there is no consensus on the best technique. This systematic review and network meta-analysis aims to characterise and identify the best reported technique for elective parenchymal liver transection based on published randomised controlled trials (RCT's).

METHODS

A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Central to identify RCT's up to 5th June 2019 that examined parenchymal transection for liver resection. Data including study characteristics and outcomes including intraoperative (blood loss, operating time) and postoperative measures (overall and major complications, bile leaks) were extracted. Indirect comparisons of all regimens were simultaneously compared using random-effects network meta-analyses (NMA) which maintains randomisation within trials.

RESULTS

This study identified 22 RCT's involving 2360 patients reporting ten parenchymal transection techniques. Bipolar cautery has lower blood loss and shorter operating time than stapler (mean difference: 85 mL; 22min) and Tissue Link (mean difference: 66 mL; 29min). Bipolar cautery was ranked first for blood loss and operating time followed by stapler and TissueLink. Harmonic scalpel is associated with lower overall complications than Hydrojet (Odds ratio (OR): 0.48), BiClamp forceps (OR: 0.46) and clamp crushing (OR: 0.41).

CONCLUSION

Bipolar cautery techniques appear to best at reducing blood loss and associated with shortest operating time. In contrast, Harmonic scalpel appears best for overall and major complications. Given the paucity of data and selective outcome reporting, it is still hard to identify what is the best technique for liver resection. Therefore, further high-quality large-scale RCT's are still needed.

Cryotherapy for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma. Liver metastases are significantly more common than primary liver cancer and long-term survival rates reported for patients after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of patients. Cryotherapy is performed with the use of an image-guided cryoprobe which delivers liquid nitrogen or argon gas to the tumour tissue. The subsequent process of freezing is associated with formation of ice crystals, which directly damage exposed tissue, including cancer cells.

OBJECTIVES

To assess the beneficial and harmful effects of cryotherapy compared with no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and six other databases up to June 2018.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of cryotherapy and its comparators for liver metastases, irrespective of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We extracted information on participant characteristics, interventions, study outcomes, and data on the outcomes important for our review, as well as information on the design and methodology of the trials. Two review authors independently assessed risk of bias in each study. One review author performed data extraction and a second review author checked entries.

MAIN RESULTS

We found no randomised clinical trials comparing cryotherapy versus no intervention or versus systemic treatments; however, we identified one randomised clinical trial comparing cryotherapy with conventional surgery. The trial was conducted in Ukraine. The trial included 123 participants with solitary, or multiple unilobar or bilobar liver metastases; 63 participants received cryotherapy and 60 received conventional surgery. There were 36 women and 87 men. The primary sites for the metastases were colon and rectum (66.6%), stomach (7.3%), breast (6.5%), skin (4.9%), ovaries (4.1%), uterus (3.3%), kidney (3.3%), intestines (1.6%), pancreas (1.6%), and unknown (0.8%). The trial was not reported sufficiently enough to assess the risk of bias of the randomisation process, allocation concealment, or presence of blinding. It was also not possible to assess incomplete outcome data and selective outcome reporting bias. The certainty of evidence was low because of risk of bias and imprecision.The participants were followed for up to 10 years (minimum five months). The trial reported that the mortality at 10 years was 81% (51/63) in the cryotherapy group and 92% (55/60) in the conventional surgery group. The calculated by us relative risk (RR) with 95% Confidence Interval (CI) was: RR 0.88, 95% CI 0.77 to 1.02. We judged the evidence as low-certainty evidence. Regarding adverse events and complications, separately and in total, our calculation showed no evidence of a difference in recurrence of the malignancy in the liver: 86% (54/63) of the participants in the cryotherapy group and 95% (57/60) of the participants in the conventional surgery group developed a new malignancy (RR 0.90, 95% CI 0.80 to 1.01; low-certainty evidence). The frequency of reported complications was similar between the cryotherapy group and the conventional surgery group, except for postoperative pain. Both insignificant and pronounced pain were reported to be more common in the cryotherapy group while intense pain was reported to be more common in the conventional surgery group. However, the authors did not report whether there was any evidence of a difference. There were no intervention-related mortality or bile leakages.We identified no evidence for health-related quality of life, cancer mortality, or time to progression of liver metastases. The study reported tumour response in terms of the carcinoembryonic antigen level in 69% of participants, and reported results in the form of a graph for 30% of participants. The carcinoembryonic antigen level was lower in the cryotherapy group, and decreased to normal values faster in comparison with the control group (P < 0.05).

FUNDING

the trial did not provide information on funding.

AUTHORS' CONCLUSIONS

The evidence for the effectiveness of cryotherapy versus conventional surgery in people with liver metastases is of low certainty. We are uncertain about our estimate and cannot determine whether cryotherapy compared with conventional surgery is beneficial or harmful. We found no evidence for the benefits or harms of cryotherapy compared with no intervention, or versus systemic treatments.

Efficacy of a Laparoscopic Saline-Coupled Bipolar Sealer in Minimally Invasive Hepatobiliary Surgery

Hepatic resection presents unique surgical challenges to reduce blood loss during parenchymal division. The development of saline-coupled bipolar devices, in which hemostasis is achieved at lower temperatures than electrocautery or other bipolar sealing devices, have been employed for open hepatic resection. Saline-coupled bipolar devices have now become available for minimally invasive use. The goals of this study were to evaluate the feasibility and safety of a laparoscopic saline-coupled bipolar device for minimally invasive hepatectomy. Seventeen patients (median age 66 years, range 36-81) were consented for inclusion and enrolled. Patient demographics, intraoperative data, and surgeon feedback were collected. Seven robot-assisted partial hepatectomies, 9 laparoscopic partial hepatectomies, and 1 laparoscopic cholecystectomy with liver abscess resection were performed. Average operating time was 222 ± 33 minutes (median 188 minutes; range 61-564 minutes) with no difference between robotic versus laparoscopic time. Successful seals were achieved in all cases following application of 150 to 200 J energy (average 179 ± 3 J, average time to achieve a successful seal 9.3 ± 2.7 minutes). Estimated blood loss was 362 ± 74 mL (median 300 mL, range 5-1200 mL) and 3/17 patients received intraoperative blood transfusion. No bile leaks were detected in any of the patients. Median length of stay was 5 days (range 1-20 days), and there were no readmissions within 30 days. Postoperative morbidity occurred in 5/17 patients, all of which were Clavien Grade 1. There was no mortality within 90 days or complications requiring a return to the operating room, and there were no liver-specific morbidities. These data suggest the laparoscopic Aquamantys device represents a useful device for use in minimally invasive liver resection.

BiClamp® vessel-sealing device for open hepatic resection of malignant and benign liver tumours: a single-institution experience

BACKGROUND

Intraoperative blood loss during hepatectomy worsens prognosis, and various tools have been used to improve perioperative safety and feasibility. We aimed to retrospectively evaluate the feasibility and safety of the BiClamp® device for open liver resection.

METHODS

We included 84 patients undergoing liver resection from a single centre, with all patients operated by the same surgical group. All hepatectomies were performed using BiClamp® (Erbe Elektromedizin GmbH, Tubingen, Germany), an electrosurgical device that simultaneously transects liver parenchyma and seals vessels <7 mm in diameter. We collected data on intraoperative blood loss, resection time, and perioperative complications, comparing cirrhotic and non-cirrhotic patients.

RESULTS

The 84 patients enrolled in this study included 56 cirrhotic and 28 non-cirrhotic patients. All patients underwent hepatectomy (30 major and 54 minor hepatectomies) using the BiClamp®, exclusively, and 54 patients required inflow occlusion (Pringle manoeuvre). Overall intraoperative blood loss (mean ± standard deviation) was 523.5 ± 558.6 ml, liver parenchymal transection time was 36.3 ± 16.5 min (range, 13-80 min), and the mean parenchymal transection speed was 3.0 ± 1.9 cm²/min. Twelve patients received perioperative blood transfusion. The cost of BiClamp® for each patient was 800 RMB (approximately 109€). There were no deaths, and the morbidity rate was 25%. The mean (standard deviation) hospital stay was 9.3 (2.3) days. Comparisons between cirrhotic and non-cirrhotic patients revealed no difference in blood loss (491.0 ± 535.7 ml vs 588.8 ± 617.5 ml, P = 0.598), liver parenchymal transection time (34.1 ± 14.8 min vs 40.9 ± 19.2 min, P = 0.208), mean parenchymal transection speed (3.3 ± 2.1 cm²/min vs 2.5 ± 1.3 cm²/min, P = 0.217), and operative morbidity (28.6% vs 14.3%, P = 0.147).

CONCLUSIONS

The reusable BiClamp® vessel-sealing device allows for safe and feasible major and minor hepatectomy, even in patients with cirrhotic liver.

TRIAL REGISTRATION

This trial was retrospectively registered and the detail information was as followed. Registration number: ChiCTR-ORC-17011873 (Chinese Clinical Trial Registry). Registration Date: 2017-07-05.

Current technical aspects of oncological hepatic surgery

BACKGROUND

With the recent advances in oncological hepatic surgery, major liver resections became more widely utilized procedures. The era of modern hepatic surgery witnessed improvements in patients care in preoperative, intraoperative and postoperative aspects. This significantly improved surgical outcomes regarding morbidity and mortality. This review article focuses on the recent advances in oncological hepatic surgery.

DATA SOURCES

This review includes only data from peer-reviewed articles and journals. PubMed database was utilized as the primary source of the supporting literature to this review article on the latest advances in oncological hepatic surgery. Comprehensive and high sensitivity search strategies were performed to search related studies exhaustively up till June 2016. We critically and independently assessed over 50 recent publications written on this topic according to the selection criteria and quality assessment standard. We paid particular attention to the studies published in high impact journals that address the use of the surgical techniques mentioned in the articles in well-known institutions.

RESULTS

Among all utilized approaches aiming at the preoperative assessment of the liver function, Child-Turcotte-Pugh classification remains the most reliable tool correlating with survival outcome. Although the primary radiological tools including ultrasonography, computed tomography and magnetic resonance imaging remain on top of the menu of tests utilized in assessment of focal hepatic lesions, intraoperative ultrasonography projects to be a powerful additional tool in terms of sensitivity and specificity compared to the other conventional techniques in assessment of the liver in the operative setting, a procedure that can change the surgical strategy in 27.2% of the cases and consequently improve the oncological surgical outcome. In addition to the conventional surgical techniques of liver resection and portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy "ALPPS" projects to be an alternative option in patients with marginally resectable tumors with an inadequate size of future liver remnant with an accepted surgical oncological outcome.

CONCLUSIONS

Considering the clinicopathological nature of hepatic lesions, the comprehensive assessment and proper choice of the liver resection technique in highly selected patients is associated with improved surgical oncological outcome. Patients with underlying marginal future liver remnant volumes can now safely benefit from a wider range of surgical intervention, a breakthrough that significantly improved morbidity and mortality in this group of patients.

Methods to decrease blood loss during liver resection: a network meta-analysis

BACKGROUND

Liver resection is a major surgery with significant mortality and morbidity. Specialists have tested various methods in attempts to limit blood loss, transfusion requirements, and morbidity during elective liver resection. These methods include different approaches (anterior versus conventional approach), use of autologous blood donation, cardiopulmonary interventions such as hypoventilation, low central venous pressure, different methods of parenchymal transection, different methods of management of the raw surface of the liver, different methods of vascular occlusion, and different pharmacological interventions. A surgeon typically uses only one of the methods from each of these seven categories. The optimal method to decrease blood loss and transfusion requirements in people undergoing liver resection is unknown.

OBJECTIVES

To assess the effects of different interventions for decreasing blood loss and blood transfusion requirements during elective liver resection.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and Science Citation Index Expanded to September 2015 to identify randomised clinical trials. We also searched trial registers and handsearched the references lists of identified trials.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) comparing different methods of decreasing blood loss and blood transfusion requirements in people undergoing liver resection.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and collected data. We assessed the risk of bias using Cochrane domains. We conducted a Bayesian network meta-analysis using the Markov chain Monte Carlo method in WinBUGS 1.4, following the guidelines of the National Institute for Health and Care Excellence Decision Support Unit guidance documents. We calculated the odds ratios (OR) with 95% credible intervals (CrI) for the binary outcomes, mean differences (MD) with 95% CrI for continuous outcomes, and rate ratios with 95% CrI for count outcomes, using a fixed-effect model or random-effects model according to model-fit. We assessed the evidence with GRADE.

MAIN RESULTS

We identified 67 randomised clinical trials involving a total of 6197 participants. All the trials were at high risk of bias. A total of 5771 participants from 64 trials provided data for one or more outcomes included in this review. There was no evidence of differences in most of the comparisons, and where there was, these differences were in single trials, mostly of small sample size. We summarise only the evidence that was available in more than one trial below. Of the primary outcomes, the only one with evidence of a difference from more than one trial under the pair-wise comparison was in the number of adverse events (complications), which was higher with radiofrequency dissecting sealer than with the clamp-crush method (rate ratio 1.85, 95% CrI 1.07 to 3.26; 250 participants; 3 studies; very low-quality evidence). Among the secondary outcomes, the only differences we found from more than one trial under the pair-wise comparison were the following: blood transfusion (proportion) was higher in the low central venous pressure group than in the acute normovolemic haemodilution plus low central venous pressure group (OR 3.19, 95% CrI 1.56 to 6.95; 208 participants; 2 studies; low-quality evidence); blood transfusion quantity (red blood cells) was lower in the fibrin sealant group than in the control (MD -0.53 units, 95% CrI -1.00 to -0.07; 122 participants; 2; very low-quality evidence); blood transfusion quantity (fresh frozen plasma) was higher in the oxidised cellulose group than in the fibrin sealant group (MD 0.53 units, 95% CrI 0.36 to 0.71; 80 participants; 2 studies; very low-quality evidence); blood loss (MD -0.34 L, 95% CrI -0.46 to -0.22; 237 participants; 4 studies; very low-quality evidence), total hospital stay (MD -2.42 days, 95% CrI -3.91 to -0.94; 197 participants; 3 studies; very low-quality evidence), and operating time (MD -15.32 minutes, 95% CrI -29.03 to -1.69; 192 participants; 4 studies; very low-quality evidence) were lower with low central venous pressure than with control. For the other comparisons, the evidence for difference was either based on single small trials or there was no evidence of differences. None of the trials reported health-related quality of life or time needed to return to work.

AUTHORS' CONCLUSIONS

Paucity of data meant that we could not assess transitivity assumptions and inconsistency for most analyses. When direct and indirect comparisons were available, network meta-analysis provided additional effect estimates for comparisons where there were no direct comparisons. However, the paucity of data decreases the confidence in the results of the network meta-analysis. Low-quality evidence suggests that liver resection using a radiofrequency dissecting sealer may be associated with more adverse events than with the clamp-crush method. Low-quality evidence also suggests that the proportion of people requiring a blood transfusion is higher with low central venous pressure than with acute normovolemic haemodilution plus low central venous pressure; very low-quality evidence suggests that blood transfusion quantity (red blood cells) was lower with fibrin sealant than control; blood transfusion quantity (fresh frozen plasma) was higher with oxidised cellulose than with fibrin sealant; and blood loss, total hospital stay, and operating time were lower with low central venous pressure than with control. There is no evidence to suggest that using special equipment for liver resection is of any benefit in decreasing the mortality, morbidity, or blood transfusion requirements (very low-quality evidence). Radiofrequency dissecting sealer should not be used outside the clinical trial setting since there is low-quality evidence for increased harm without any evidence of benefits. In addition, it should be noted that the sample size was small and the credible intervals were wide, and we cannot rule out considerable benefit or harm with a specific method of liver resection.

Randomized clinical trial comparing two vessel-sealing devices with crush clamping during liver transection

Background

Previous RCTs have failed to demonstrate the usefulness of combining energy devices with the conventional clamp crushing method to reduce blood loss during liver transection. Here, the combination of an ultrasonically activated device (UAD) and a bipolar vessel-sealing device (BVSD) with crush clamping was investigated.

Methods

Patients scheduled to undergo hepatectomy at the University of Tokyo Hospital or Nihon University Itabashi Hospital were eligible for this parallel-group, single-blinded randomized study. Patients were assigned to a control group (no energy device used), an UAD group or a BVSD group. The primary endpoint was the volume of blood loss during liver transection. Outcomes of the control group and the combined energy device groups (UAD plus BVSD) were first compared. Pairwise comparisons among the three groups were made for outcomes for which the combined energy device group was superior to the control group.

Results

A total of 380 patients were enrolled between July 2012 and May 2014; 116 patients in the control group, 122 in the UAD group and 123 in the BVSD group were included in the final analysis. Median blood loss during liver transection was lower in the combined energy device group (245 patients) than in the control group (116 patients): median 190 (range 0–3575) versus 230 (range 3–1570) ml (P = 0·048). Pairwise comparison revealed that blood loss was lower in the BVSD group than in the control group (P = 0·043).

Conclusion

The use of energy devices combined with crush clamping reduced blood loss during liver transection. Registration number: C000008372 (www.umin.ac.jp/ctr/index.htm).

Expert opinion on advanced techniques for hemostasis in liver surgery

BACKGROUND

Reduction of perioperative blood loss and intraoperative transfusion are two major factors associated with improving outcomes in liver surgery. There is currently no consensus as to the best technique to achieve this.

METHODS

An international Panel of Experts (EP), made up of hepatobiliary surgeons from well-known high-volume centres was assembled to share their experience with regard to the management of blood loss during liver resection surgery. The process included: a review of the current literature by the panel, a face-to-face meeting and an on-line survey completed by the EP prior to and following the face-to-face meeting, based on predetermined case scenarios. During the meeting the most frequently researched surgical techniques were appraised by the EP in terms of intraoperative blood loss.

RESULTS

All EP members agreed that high quality research on the subject was lacking. Following an agreed risk stratification algorithm, the EP concurred with the existing research that a haemostatic device should always be used along with any user preferred surgical instrumentation in both open and laparoscopic liver resection procedures, independently from stratification of bleeding risk. The combined use of Ultrasonic Dissector (UD) and saline-coupled bipolar sealing device (Aquamantys(®)) was the EP preferred technique for both open and laparoscopic surgery.

CONCLUSIONS

This EP propose the use of a bipolar sealer and UD for the best resection technique and essential equipment to minimise blood loss during liver surgery, stratified according to transfusion risk, in both open and laparoscopic liver resection.

[Liver transection: modern procedure: Technique, results and costs]

Liver resection has developed into the current standard procedure due to modern resection techniques, profound knowledge of the liver anatomy and optimized surgical and anesthesiological strategies to allow extended resections with both low morbidity and mortality. Initially major blood loss was the biggest concern with liver resection and a Pringle's manoeuvre was necessary. Nowadays, biliary leakage is the major problem after liver surgery. Besides the classical conventional clamp crushing technique for parenchymal transection, various devices including ultrasound, microwaves and staplers have been introduced. Minimally invasive techniques have become increasingly important for liver resection but are still applied in selected patients only. The selection of the resection technique and device mainly depends on the extent of the resection and also on the liver parenchyma, the liver disease, costs, personal experiences and preferences. This article presents a selection of techniques used in modern parenchymal transection during liver resection with special focus on transection time, blood loss, bile leakage and costs.

Hemostasis and Hepatic Surgery

Operative blood loss is a major source of morbidity and even mortality for patients undergoing hepatic resection. This review discusses strategies to minimize blood loss and the utilization of allogeneic blood transfusion pertaining to oncologic hepatic surgery.

Evaluation of a newly developed piezo actuator-driven pulsed water jet system for liver resection in a surviving swine animal model

Background

Preservation of the hepatic vessels while dividing the parenchyma is key to achieving safe liver resection in a timely manner. In this study, we assessed the feasibility of a newly developed, piezo actuator-driven pulsed water jet (ADPJ) for liver resection in a surviving swine model.

Methods

Ten domestic pigs underwent liver resection. Parenchymal transection and vessel skeletonization were performed using the ADPJ (group A, n = 5) or an ultrasonic aspirator (group U, n = 5). The water jet was applied at a frequency of 400 Hz and a driving voltage of 80 V. Physiological saline was supplied at a flow rate of 7 ml/min. After 7 days, the animals were killed and their short-term complications were examined and compared between the two groups.

Results

No significant complications, such as massive bleeding, occurred in either group during the surgical procedures. The transection time per transection area was significantly shorter in group A than in group U (1.5 ± 0.3 vs. 2.3 ± 0.5 min/cm², respectively, P = 0.03). Blood loss per transection area was not significantly different between groups A and U (9.3 ± 4.2 vs. 11.7 ± 2.3 ml/cm², P = 0.6). All pigs in group A survived for 7 days. No postoperative bleeding or bile leakage was observed in any animal at necropsy.

Conclusion

The present results suggested that the ADPJ reduces transection time without increasing blood loss. ADPJ is a safe and feasible device for liver parenchymal transection.

Short- and long-term outcomes of hepatectomy with or without radiofrequency-assist for the treatment of hepatocellular carcinomas: a retrospective comparative cohort study

The objective of this study was to compare the short- and long-term outcomes of radiofrequency-assisted liver resection (RFLR) and conventional clamp-crushing liver resection (CCLR) and to evaluate the safety and efficiency of RFLR. Between January 2008 and December 2012, a total of 597 patients with hepatocellular carcinoma (HCC) who underwent curative hepatectomy were identified. A total of 272 patients underwent RFLR, and 325 patients received CCLR. The short- and long-term outcomes were compared. The patients in the RFLR and CCLR groups showed similar baseline characteristics. The RFLR group showed less intraoperative blood loss (485.5 vs. 763.2 mL, p = 0.003), a lower transfusion requirement rate (19.1 vs. 31.7%, p ≤ 0.01), shorter surgery duration (211 vs. 296 min, p ≤ 0.01) and a lower vascular inflow occlusion rate (25.7 vs. 33.8%, p = 0.032). No significant postoperative changes in bilirubin or liver enzymes were observed in the two groups. The degree of postoperative complications and morbidity did not significantly differ between the two groups. There were no significant differences in the 1-, 2- and 3-year overall survival rates (73.8%, 58.5%, and 55.7% vs. 80.8%, 65.8%, and 56.2%, respectively) or disease-free rates (51.9%, 47.2%, and 46.0% vs. 54.5%, 44.9%, and 38.5%, respectively) between the RFLR and CCLR groups. These results suggested RFLR was a safe and efficient method for patients with HCC. RFLR was associated with decreased blood loss, fewer blood transfusions, shorter surgery times and less vascular inflow occlusion application. The RFLR group did not show increased liver injury or postoperative morbidity or mortality.

Skeletonization and Isolation of the Glissonean and Venous Branches in Liver Surgery With an Ultrasonic Scalpel Technology

This study describes a novel technique for skeletonization and isolation of Glissonean and venous branches during liver surgery using a harmonic scalpel (HS). Hepatic resections with HS were performed with the skeletonization and isolation technique in 50 patients (HS group). Variables evaluated were blood loss, operative time, biliary leak, and morbidity. The results were compared with 50 hepatic resections that were performed using a previously established technique: Cavitron ultrasonic surgical aspirator with electric cautery, ligatures, and hemoclips (NHS group). The HS group had shorter total operative times (285 versus 358 minutes; P = 0.01), less blood loss (389 versus 871 mL; P = 0.034), and less crystalloid infusion (2744 versus 3299 mL; P = 0.027) compared with the NHS group. Postoperative liver function and complication rates were similar when comparing the two groups. These data demonstrate that HS is a simple, easy, and effective instrument for the skeletonization and isolation of vessels during liver transection.

Role of surgical resection for hepatocellular carcinoma based on Japanese clinical guidelines for hepatocellular carcinoma

In the Algorithm for Diagnosis and Treatment in the Japanese Evidence-Based Clinical Practice Guidelines for Hepatocellular Carcinoma, the treatment strategy is determined by three major factors: liver function and the number and size of tumors. The algorithm is quite simple, consisting of fewer components than the Barcelona-Clinic Liver Cancer staging system. In this article, we describe the roles of the treatment algorithm in hepatectomy and perioperative management of hepatocellular carcinoma.

The dissection profile and mechanism of tissue-selective dissection of the piezo actuator-driven pulsed water jet as a surgical instrument: laboratory investigation using Swine liver

BACKGROUND/PURPOSE

The water jet technique dissects tissue while sparing cord-like structures such as blood vessels. The mechanism of such tissue-selective dissection has been unknown. The novel piezo actuator-driven pulsed water jet (ADPJ) system can achieve dissection with remarkably reduced water consumption compared to the conventional water jet; however, the system's characteristics and dissection capabilities on any organ have not been clarified. The purposes of this study were to characterize the physical properties of the novel ADPJ system, evaluate the dissection ability in swine organs, and reveal the mechanism of tissue-selective dissection.

METHODS

The pulsed water jet system comprised a pump chamber driven by a piezo actuator, a stainless steel tube, and a nozzle. The peak pressure of the pulsed water jet was measured through a sensing hole using a pressure sensor. The pulsed water jet technique was applied on swine liver in order to dissect tissue on a moving table using one-way linear ejection at a constant speed. The dissection depth was measured with light microscopy and evaluated histologically. The physical properties of swine liver were evaluated by breaking strength tests using tabletop universal testing instruments. The liver parenchyma was also cut with three currently available surgical devices to compare the histological findings.

RESULTS

The peak pressure of the pulsed water jet positively correlated with the input voltage (R(2) = 0.9982, p < 0.0001), and this was reflected in the dissection depth. The dissection depth negatively correlated with the breaking strength of the liver parenchyma (R(2) = 0.6694, p < 0.0001). The average breaking strengths of the liver parenchyma, hepatic veins, and Glisson's sheaths were 1.41 ± 0.45, 8.66 ± 1.70, and 29.6 ± 11.0 MPa, respectively. The breaking strength of the liver parenchyma was significantly lower than that of the hepatic veins and Glisson's sheaths. Histological staining confirmed that the liver parenchyma was selectively dissected, preserving the hepatic veins and Glisson's sheaths in contrast to what is commonly observed with electrocautery or ultrasonic instruments.

CONCLUSIONS

The dissection depth of liver tissue is well controlled by input voltage and is influenced by the moving velocity and the physical properties of the organ. We showed that the device can be used to assure liver resection with tissue selectivity due to tissue-specific physical properties. Although this study uses an excised organ, further in vivo studies are necessary. The present work demonstrates that this device may function as an alternative tool for surgery due to its good controllability of the dissection depth and ability of tissue selectivity.

Decreased blood loss reduces postoperative complications in resection for hepatocellular carcinoma

BACKGROUND

The correlation between blood loss and the risk of postoperative complications was unclear in patients undergoing resection of hepatocellular carcinoma (HCC).

METHODS

We studied 539 patients who had resection of HCC. Postoperative complications were recorded according to the modified Clavien-Dindo classification. Variables were compared between patients with grade III to V complications and those with no or grade I to II. A spline regression analysis was used to estimate the probability of grade III to V complications.

RESULTS

Among variables, blood loss (P = 0.0001), operating time (P = 0.0001), blood transfusion (P = 0.0001), and tumor size (P = 0.02) differed significantly between patients with grade III to V and those with no or I to II. Multivariate analysis revealed that the factor most strongly related to complications was blood loss (odds ratio 1.68; 95% confidence interval [CI] 1.45-1.96, P = 0.0001). Spline regression analysis showed that an increase in blood loss was accompanied by increase in the risk of complication; when the estimated probability of grade III to V complications exceeded 50% (95% CI 30.0-70.0), the corresponding blood loss was 820 ml.

CONCLUSION

Decrease in blood loss in resection of HCC is accompanied by reduced risk of complications. Surgeons need to minimize blood loss as less as 820 ml.

Stereotactic excision of additional lesions detected with intraoperative ultrasound examination during radiofrequency dissecting sealar (habib®) assisted hepatic metastasectomy: report of 4 cases

Intraoperative ultrasound has been using to achieve a proper resection strategy in patients undergoing a hepatic colorectal metastasectomy. This study aims to describe and reveal the place of stereotactic metastasectomy in nonpalpable colorectal liver metastases (CLM). A chart review was initiated for all patients underwent resection for CLM between 2006 and 2011. The data concerning perioperative data and intraoperative strategy were abstracted. Among the 58 patients, who underwent a resection for CLM, 4 (6.9 %) (all men, median age 65.5, range 49-72, years) necessitated a stereotactic metastasectomy. Preoperative evaluations showed 1 (n = 1), 2 (n = 2), or 3 (n = 1) lesions, and intraoperative ultrasound (IUS) found an additional lesion in a case. Stereotactic marking was performed for nonpalpable lesions located in segments IVA, II, and VI and at the junction of segments V and VI. The margins were negative for all lesions both resected with conventional and stereotactic techniques. The examinations of the stereotactic resection materials revealed metastatic adenocarcinoma (patients n = 2), focal nodular hyperplasia (n = 1), and abnormal benign liver histology probably induced by chemotherapy (n = 1). The median (range) operation and hospitalization periods were 217.5 (150-310) minutes and 5.5 (2-9) days. No complications were observed except biliary fistula in a case, which spontaneously disappeared within 2 weeks. A patient died due to systemic disease including hepatic metastases 33 months after the liver surgery. Stereotactic metastasectomy may be feasible for the removal of nonpalpable CLM. Further evaluations are necessitated to understand the accurate place of this novel technique.

Methods to decrease blood loss during liver resection: a network meta-analysis

BACKGROUND

Liver resection is a major surgery with significant mortality and morbidity. Various methods have been attempted to decrease blood loss and morbidity during elective liver resection. These methods include different methods of vascular occlusion, parenchymal transection, and management of the cut surface of the liver. A surgeon typically uses only one of the methods from each of these three categories. Together, one can consider this combination as a treatment strategy. The optimal treatment strategy for liver resection is unknown.

OBJECTIVES

To assess the comparative benefits and harms of different treatment strategies that aim to decrease blood loss during elective liver resection.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Science Citation Index Expanded to July 2012 to identify randomised clinical trials. We also handsearched the references lists of identified trials.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) where the method of vascular occlusion, parenchymal transection, and management of the cut surface were clearly reported, and where people were randomly assigned to different treatment strategies based on different combinations of the three categories (vascular occlusion, parenchymal transection, cut surface).

DATA COLLECTION AND ANALYSIS

Two review authors identified trials and collected data independently. We assessed the risk of bias using The Cochrane Collaboration's methodology. We conducted a Bayesian network meta-analysis using the Markov chain Monte Carlo method in WinBUGS 1.4 following the guidelines of the National Institute for Health and Care Excellence Decision Support Unit guidance documents. We calculated the odds ratios (OR) with 95% credible intervals (CrI) (which are similar to confidence intervals in the frequentist approach for meta-analysis) for the binary outcomes and mean differences (MD) with 95% CrI for continuous outcomes using a fixed-effect model or random-effects model according to model-fit.

MAIN RESULTS

We identified nine trials with 617 participants that met our inclusion criteria. Interventions in the trials included three different options for vascular occlusion, four for parenchymal transection, and two for management of the cut liver surface. These interventions were combined in different ways in the trials giving 11 different treatment strategies. However, we were only able to include 496 participants randomised to seven different treatment strategies from seven trials in our network meta-analysis, because the treatment strategies from the trials that used fibrin sealant for management of the raw liver surface could not be connected to the network for any outcomes. Thus, the trials included in the network meta-analysis varied only in their approaches to vascular exclusion and parenchymal transection and none used fibrin sealant. All the trials were of high risk of bias and the quality of evidence was very low for all the outcomes. The differences in mortality between the different strategies was imprecise (seven trials; seven treatment strategies; 496 participants). Five trials (six strategies; 406 participants) reported serious adverse events. There was an increase in the proportion of people with serious adverse events when surgery was performed using radiofrequency dissecting sealer compared with the standard clamp-crush method in the absence of vascular occlusion and fibrin sealant. The OR for the difference in proportion was 7.13 (95% CrI 1.77 to 28.65; 15/49 (adjusted proportion 24.9%) in radiofrequency dissecting sealer group compared with 6/89 (6.7%) in the clamp-crush method). The differences in serious adverse events between the other groups were imprecise. There was a high probability that 'no vascular occlusion with clamp-crush method and no fibrin' and 'intermittent vascular occlusion with Cavitron ultrasonic surgical aspirator and no fibrin' are better than other treatments with regards to serious adverse events. Quality of life was not reported in any of the trials.The differences in the proportion of people requiring blood transfusion was imprecise (six trials; seven treatments; 446 participants). Two trials (three treatments; 155 participants) provided data for quantity of blood transfused. People undergoing liver resection by intermittent vascular occlusion had higher amounts of blood transfused than people with continuous vascular occlusion when the parenchymal transection was carried out with the clamp-crush method and no fibrin sealant was used for the cut surface (MD 1.2 units; 95% CrI 0.08 to 2.32). The differences in the other comparisons were imprecise (very low quality evidence). Three trials (four treatments; 281 participants) provided data for operative blood loss. People undergoing liver resection using continuous vascular occlusion had lower blood loss than people with no vascular occlusion when the parenchymal transection was carried out with clamp-crush method and no fibrin sealant was used for the cut surface (MD -130.9 mL; 95% CrI -255.9 to -5.9). None of the trials reported the proportion of people with major blood loss.The differences in the length of hospital stay (six trials; seven treatments; 446 participants) and intensive therapy unit stay (four trials; six treatments; 261 participants) were imprecise. Four trials (four treatments; 245 participants) provided data for operating time. Liver resection by intermittent vascular occlusion took longer than liver resection performed with no vascular occlusion when the parenchymal transection was carried out with Cavitron ultrasonic surgical aspirator and no fibrin sealant was used for the cut surface (MD 49.6 minutes; 95% CrI 29.8 to 69.4). The differences in the operating time between the other comparisons were imprecise. None of the trials reported the time needed to return to work.

AUTHORS' CONCLUSIONS

Very low quality evidence suggested that liver resection using a radiofrequency dissecting sealer without vascular occlusion or fibrin sealant may increase serious adverse events and this should be evaluated in further randomised clinical trials. The risk of serious adverse events with liver resection using no special equipment compared with more complex methods requiring special equipment was uncertain due to the very low quality of the evidence. The credible intervals were wide and considerable benefit or harm with a specific method of liver resection cannot be ruled out.

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.

A prospective randomized controlled trial of hemostasis with a bipolar sealer during hepatic transection for liver resection

BACKGROUND

Excessive intraoperative blood loss and the possible requirement for blood transfusion are major problems in hepatic resection for liver tumors. The decrease of blood loss is a goal in liver surgery, and several technical developments have been introduced for this purpose. The aim of this prospective randomized study was to compare the use of the Cavitron Ultrasonic Surgical Aspirator (CUSA) with a radiofrequency-based bipolar hemostatic sealer versus CUSA with standard bipolar cautery (BC) in patients undergoing hepatic resection.

METHODS

One hundred nine patients with liver tumors were randomized to undergo hepatic transection via CUSA with a bipolar sealer (Aquamantys 2.3 Bipolar Sealer; n = 55) or BC (n = 54). Blood loss during parenchymal transection and speed of transection were the primary end points, whereas the degree of postoperative liver injury and morbidity were secondary end points.

RESULTS

Compared with the BC group, the bipolar sealer showed lesser blood loss during transection and blood loss divided by resection area (P = .0079 and .0008, respectively), shorter transection time (P = .0025), faster speed of transection (P < .0001), and fewer ties and ties divided by resection area required during transection (P < .0001).

CONCLUSION

CUSA with a bipolar sealer is superior to CUSA with standard BC for various hepatectomy in terms of less blood loss and faster speed of transection, with no increase in morbidity.

Technology-Assisted Versus Clamp-Crush Liver Resection

Objective. To review the published evidence on technology-assisted liver resection regarding operative time, intraoperative bleeding, mortality, hospital stay, postoperative bile leak, and other outcomes. Method. A systematic review of clinical studies comparing liver resection using vessel sealing systems (VSSs—LigaSure), Cavitron Ultrasonic Surgical Aspirator (CUSA), or radiofrequency dissecting sealer (RFDS) with the conventional clamp-crushing technique (CC) was performed. Data for each modality were synthesized and individually compared with CC with the methodology of meta-analysis. Result. In all, 8 randomized controlled trials (RCTs) and 7 nonrandomized studies evaluating 1539 patients were included. Compared with CC, the VSS group (3 RCTs and 3 nonrandomized studies) had significantly lower blood loss by a mean of 109 mL (weighted mean difference [WMD] = −109; 95% confidence interval [CI] = −192, −26; data on 494 patients), lower risk for postoperative bile leak by 63% (odds ratio [OR] = 0.37; CI = 0.17, 0.78; 559 patients), and shorter total hospital stay by 2 days (WMD = −2.04; CI = −3.08, −1; 340 patients); no difference was noted for liver parenchyma transection time and mortality. No difference was noted between CUSA (4 RCTs and 1 nonrandomized study) or RFDS (3 RCTs and 3 nonrandomized studies) versus CC for any of the studied outcomes. Conclusion. Of the 3 modalities used in liver resection (VSS, CUSA, and RFDS), only VSS appeared to offer significant benefit over standard CC. However, the generalization of our findings is limited by the scarcity and clinical heterogeneity of the published studies. Large, well-designed and implemented RCTs are warranted to further investigate the usefulness of novel modalities used in liver resection.

Comprehensive application of modern technologies in precise liver resection

BACKGROUND

Liver surgery has gone through the phases of wedge liver resection, regular resection of hepatic lobes, irregular and local resection, extracorporeal hepatectomy, hemi-extracorporeal hepatectomy and Da Vinci surgical system-assisted hepatectomy. Taking advantage of modern technologies, liver surgery is stepping into an age of precise liver resection. This review aimed to analyze the comprehensive application of modern technologies in precise liver resection.

DATA SOURCE

PubMed search was carried out for English-language articles relevant to precise liver resection, liver anatomy, hepatic blood inflow blockage, parenchyma transection, and down-staging treatment.

RESULTS

The 3D image system can imitate the liver operation procedures, conduct risk assessment, help to identify the operation feasibility and confirm the operation scheme. In addition, some techniques including puncture and injection of methylene blue into the target Glisson sheath help to precisely determine the resection. Alternative methods such as Pringle maneuver are helpful for hepatic blood inflow blockage in precise liver resection. Moreover, the use of exquisite equipment for liver parenchyma transection, such as cavitron ultrasonic surgical aspirator, ultrasonic scalpel, Ligasure and Tissue Link is also helpful to reduce hemorrhage in liver resection, or even operate exsanguinous liver resection without blocking hepatic blood flow. Furthermore, various down-staging therapies including transcatheter arterial chemoembolization and radio-frequency ablation were appropriate for unresectable cancer, which reverse the advanced tumor back to early phase by local or systemic treatment so that hepatectomy or liver transplantation is possible.

CONCLUSIONS

Modern technologies mentioned in this paper are the key tool for achieving precise liver resection and can effectively lead to maximum preservation of anatomical structural integrity and functions of the remnant liver. In addition, large randomized trials are needed to evaluate the usefulness of these technologies in patients with hepatocellular carcinoma who have undergone precise liver resection.

Radiofrequency-assisted versus clamp-crushing parenchyma transection in cirrhotic patients with hepatocellular carcinoma: a randomized clinical trial

BACKGROUND

Surgical resection remains the optimal therapy for cirrhotic patients with hepatocellular carcinoma (HCC) that are not suitable for liver transplantation (LT). Recently, various innovative techniques for liver resection have been developed.

AIM

The aim of the study was to compare radiofrequency-assisted parenchyma transection (RF-PT) with the traditional clamp-crushing (CC) technique to explore the preferred therapy in cirrhotic patients with HCC.

METHODS

From January 2009 to December 2010, 75 cirrhotic patients with HCC who underwent hepatectomy were randomized to RF-PT (group 1, n = 38) or CC-PT (group 2, n = 37) groups. The primary endpoint was intraoperative blood loss. The secondary endpoints included hepatic transection time, total operating time, postoperative morbidity, mortality, length of intensive care unit and hospital stays, and liver function.

RESULTS

The characteristics of the two patient groups were closely matched. The Pringle maneuver was not used in RF-PT patients. The blood loss of the RF-PT group, total or during transection, was significantly lower than that of the CC-PT group (385 vs. 545 ml, p = 0.001; 105 vs. 260 ml, p = 0.000, respectively). Compared with CC-PT patients, the morbidity of the RF-PT group was lower though not statistically significant (28.9 vs. 38.8 %, p = 0.197). One death occurred in the RF-PT group 12 days postoperative due to a large area cerebral embolism.

CONCLUSION

RF-PT is a safe and feasible surgical resection method for patients with cirrhosis and concomitant HCC. In addition, RF-PT results in lower blood loss and lower morbidity than the CC technique during liver resection.

A worldwide survey of the current daily practice in liver surgery

BACKGROUND

Liver resection remains the mainstay of curative treatment for liver malignancies. A variety of preoperative assessments and surgical techniques have improved the short- and long-term outcomes of liver resection in patients with liver tumors. Recently, laparoscopic hepatectomies have been increasingly performed. The aim of the present study is to survey the current practice of liver surgery in high-volume centers in the world.

METHODS

A questionnaire on the preoperative assessment for liver surgery, open hepatectomy, and laparoscopic hepatectomy was sent to 94 liver centers in the world.

RESULTS

Forty-two centers (45%) responded to this survey (29 Asian, 9 European, and 4 North American centers). All but one of the centers evaluated the future liver remnant (FLR) volume, and 95% of them performed preoperative portal vein embolization to increase the FLR volume. In half of the centers, the required FLR volume was over 30% in patients with normal liver and 50% in patients with cirrhotic liver. To reduce the intraoperative blood loss, half of the centers routinely used Pringle's maneuver, and 85% restricted the intraoperative fluid infusion to reduce the central venous pressure. More than 10 laparoscopic hepatectomies were performed per year in 62% of the centers, and more than 30 were performed in 26%, respectively. Laparoscopic major hepatectomies were performed in 24%. Two-thirds answered that the laparoscopic approach would be feasible in donor hepatectomy.

CONCLUSION

The evaluation of FLR volume in patients with normal or cirrhotic liver and the usage of preoperative portal vein embolization have become essential practice in more than 90% of the centers. Reduced blood loss has been achieved using Pringle's maneuver, restriction of fluid infusion, and a variety of surgical devises. The laparoscopic approach is increasingly extended to major hepatectomy or donor hepatectomy.

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.

Modified conventional clamp-crushing technique in liver parenchymal transection

Significant intraoperative bleeding and injuries to vital structures in the liver remnant can occur during liver parenchymal transection using the conventional clamp-crushing technique. We performed liver resection on 242 patients using a mosquito clamp-crushing technique combined with a self-assembled saline-linked diathermy for liver parenchymal transection. The mean blood loss was 215 mL (range 20-1100). There was no damage to the vital structures in the liver remnant. The mean liver transection time was 53 minutes (range 15-125). Our technique has the advantages of reducing blood loss, exposing vessles clearly and being simple, cheap and efficacious.

Radiofrequency-assisted liver resection with a comb-shaped bipolar device versus clamp crushing: a clinical study

BACKGROUND

In liver surgery, clamp-crushing (CC) procedure has been shown to be the most efficient system for liver transection. Recently, it has been suggested that radiofrequency-assisted liver resection (RFALR) may be more advantageous, but sufficient evidence has yet to be accumulated.

METHOD

The control group was constituted by 32 patients undergoing CC liver transection. The study group included 13 patients undergoing RFALR with a new fully automated radiofrequency generator supplying a comb-shaped bipolar multielectrode device.

RESULTS

RFALR allowed a faster hepatic transection and reduced both surgical time and intraoperative blood loss. RFALR was the only independent prognostic indicator of bleeding during liver transection. No significant liver damage and postoperative complications, particularly biliary leakage and stenosis, were experienced in the RFALR group.

CONCLUSION

Compared with the CC procedure, this bipolar device was shown to be safe and effective in liver resections, allowing a very clean surgical field without increase of postoperative complications.

[Sutureless hepatic transection using a new radiofrequency assisted device. Theoretical model, experimental study and clinic trial]

The ideal instrument for performing hepatic transection should combine safe and rapid haemostasis in a single tool. We present a new multidisciplinary investigation designed to develop a hepatic transection device assisted by radiofrequency (RF); the investigation included: a computerised theoretical model, and experimental study and a clinical trial of this device. The theoretic modelling was performed by computer, based on the Finite Elements Method (FEM), with the objective of studying the distribution of electrical energy and temperature in the tissue, and to assess the effect of the characteristics of the instrument. The experimental study, based on an in vivo porcine model, suggested that the new instrument would allow the transection velocity of the hepatic parenchyma to be increased with lower bleeding per transection area compared with other techniques extensively used in liver surgery. These data should enable the first phase of clinical trial to be conducted, with preliminary results that suggest that the new device is safe and effective.

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.

A novel method using the VIO soft-coagulation system for liver resection

BACKGROUND

The VIO soft-coagulation system (SCS) is a new device for tissue coagulation. The current study evaluated the efficacy of the SCS when used for liver resection.

METHODS

The 252 patients were divided into 2 groups; in 155 patients (conventional group), liver transection was performed using an ultrasonic dissector and saline-coupled bipolar electrocautery for hemostasis. In 97 patients (SCS group), the SCS was used instead of bipolar electrocautery.

RESULTS

The median blood loss and surgical time were less in the SCS group than in the conventional group (350 vs 640 mL, P = .0028; 280 vs 398 min, P < .0001). No significant differences were found in postoperative complications between the SCS group (32.0%) and the conventional group (40.6%). The risk factors for bleeding were nonuse of the SCS (P = .0039), macroscopic vascular invasion of the hepatic tumors (P = .0088), and collagen type IV value in the sera >200 (P = .0250) on multivariate analysis. In a subgroup analysis, in the collagen type IV value >200 subgroup, the tumor diameter >5 cm subgroup, and the inflow nonocclusion subgroup, use of the SCS decreased surgical bleeding (P = .0120, P = .0126, and P = .0032, respectively) and surgical time (P = .0001, P < .0001, and P = .0036, respectively) compared with the conventional group. Furthermore, even in the major hepatectomy group, the SCS use decreased surgical time (P < .0001).

CONCLUSION

The SCS is an effective and safe device for decreasing surgical time and surgical bleeding without increasing the rate of bile leakage and causing other complications.

Liver Resection Using a Four-Prong Radiofrequency Transection Device

Multiple techniques are available for division of hepatic parenchyma. This is the largest United States report examining the use of the Habib 4X tissue coagulator (AngioDynamics, Queensbury, NY). The objective was to collect standard parameters associated with successful, benchmarked liver surgery outcomes using this new device, and in particular, examine the risk of margin failure. Ninety-four consecutive operations using the Habib 4X were analyzed with special attention to local failure at resection margin, blood loss/transfusion, and operative times. An institutional review board approved protocol allowed collection and analysis of demographic information and outcomes for intraoperative, perioperative, and long term follow-up. Eighteen patients had biopsy only. Thirty-one had lobar resections and 46 had wedge or segmental resections. There were 30 primary hepatic and 46 metastatic tumor diagnoses. There were a total of 33 (43%) recurrences with a mean time to recurrence of 212 days (range 15-974). Of the 27 intrahepatic recurrences, four (15%) were at the margin. The OR time ranged from 115 to 642 minutes (average 283 min). The average recorded blood loss was 427 mL; 11 patients were transfused (average 0.43 units). The Habib 4X is a safe tool to use when evaluating the parameters of blood loss, transfusion, and margin recurrence.

Surgical treatment of hepatocellular carcinoma

Local tumor control is still the most important consideration in the treatment of hepatocellular carcinoma (HCC). Surgical treatments, including liver resection and liver transplantation are, and will remain, the first-line therapeutic strategies for local control in patients with primary HCC. Although aggressive liver resection is often performed for advanced HCC in patients with a large tumor, multiple tumors, or tumors with vascular invasion, liver transplantation is the preferred option, after taking into consideration age and tumor-related factors, when there is poor liver functional reserve. Preventing deterioration in liver function is the second priority in the treatment of HCC. When performing liver resection, extensive removal of noncancerous liver parenchyma during lobectomy or hemihepatectomy, should be avoided as much as possible. Anatomic resection, which refers to systematic elimination of the main tumor with its minute metastases, preserves liver function and is highly recommended. A treatment algorithm based on published evidence is now available, which helps us decide on the most suitable therapeutic option for individual patients, depending on the tumor characteristics and liver functional reserve.

Feasibility of randomized controlled trials in liver surgery using surgery-related mortality or morbidity as endpoint

BACKGROUND

There is a shortage of randomized controlled trials (RCTs) on which to base guidelines in liver surgery. The feasibility of conducting an adequately powered RCT in liver surgery using the dichotomous endpoints surgery-related mortality or morbidity was examined.

METHODS

Articles published between January 2002 and November 2007 with mortality or morbidity after liver surgery as primary endpoint were retrieved. Sample size calculations for a RCT aiming to show a relative reduction of these endpoints by 33, 50 or 66 per cent were performed.

RESULTS

The mean operative mortality rate was 1.0 per cent and the total morbidity rate 28.9 per cent; mean rates of bile leakage and postresectional liver failure were 4.4 and 2.6 per cent respectively. The smallest numbers of patients needed in each arm of a RCT aiming to show a 33 per cent relative reduction were 15 614 for operative mortality, 412 for total morbidity, 3446 for bile leakage and 5924 for postresectional liver failure.

CONCLUSION

The feasibility of conducting an adequately powered RCT in liver surgery using outcomes such as mortality or specific complications seems low. Conclusions of underpowered RCTs should be interpreted with caution. A liver surgery-specific composite endpoint may be a useful and clinically relevant solution to pursue.

The vessel sealing system (LigaSure) in hepatic resection: a randomized controlled trial

OBJECTIVE

The aim of this trial was to verify the new surgical device (the LigaSure vessels sealing system) decrease liver transection time.

SUMMARY BACKGROUND DATA

Among the major goals in hepatic resection are minimization of the operation time and of the blood loss. Preliminary reports have suggested that the vessel sealing system might decrease the liver transection time, which is directly associated with the amount of blood loss.

METHODS

Patients who were scheduled to undergo hepatic resection at the Tokyo University Hospital were assigned, by the minimization method, to either use of the new vessel sealing system (VS group) or the conventional clamp crushing method (CC group) for liver transection. The primary end point was the liver transection time, and the secondary endpoints were the amount of blood loss during the entire operation and during liver transection, length of hospital stay, postoperative liver function, and the incidence of various adverse events. An English-language summary of the protocol was submitted (registration ID: C000000337) to the Clinical Trials Registry managed by the University Hospital Medical Information Network in Japan, which can be accessed commission-free on the internet (Available at: http://www.umin.ac.jp/ctr/index.htm).

RESULTS

From February to December in 2006, a total of 165 patients underwent liver resection for some benign or malignant disease of the liver. Among these patients, 120 were randomly assigned to the CC (n = 60) or the VS (n = 60) group. There was no mortality in either of the 2 groups. The median liver transection time in the VS group was 57 minutes (range: 11-127), similar to that in the CC group (56 [range: 9-269] min, P = 0.64), while there was no difference in the transection speed between the 2 groups (1.16 [0.15-2.26] cm/min vs. 1.10 [0.15-2.66] cm/min, P = 0.95). The amount of blood loss and blood loss per transection area during liver transaction in the VS group was also similar to that in the CC group (median: 315 [25-2415] mL vs. 315 [10-1700] mL; P = 0.80) and (5.04 [1.01-44.2] mL/cm vs. 4.36 [0.15-50.5] mL/cm; P = 0.14), respectively.

CONCLUSIONS

This randomized controlled trial showed that while the vessel sealing system was safe, its use was not associated with any significant decrease of the operation time or blood loss during liver transaction as compared with that of the clamp crushing method.

[Solid organ transection. Open and laparoscopic surgery]

Recent advances in liver surgery have reduced post-hepatectomy mortality to less than 5% in most units specialized in hepato-pancreatic-biliary surgery. Possibly, the single most important factor contributing to these improved results has been the reduction in intraoperative bleeding during liver parenchymal transection. Liver transection is the most risky part of the intervention due to the risk of massive hemorrhage. Some technological advances and refinements to the surgical technique have contributed to making this critical phase of liver surgery safer. Among these advances, the most notable are detailed knowledge of the surgical anatomy of the liver, vascular control techniques and methods of liver parenchymal transection. The present review describes current transection techniques, as well as their advantages and disadvantages. Until there is solid evidence on the best method, the choice of technique and instrument for liver transection depends mainly on the surgeon's personal preference. Nevertheless, some factors can influence the choice of method, such as the surgeon's experience, anesthetic management, type of hepatectomy (central, peripheral), type of approach (open, laparoscopic), quality of the liver (normal, cirrhotic, steatotic) and the availability of the instruments in the center.

Bloodless hepatic resection with automatic bipolar radiofrequency generator and multielectrode device

Liver resection is a standard treatment for liver tumours. Intra-operative blood loss remains a major concern during liver resection due to its association with higher postoperative complications and shorter long-term survival. To perform bloodless hepatic resection we realized an apparatus consisting of an incremental, bipolar radiofrequency generator and a probe with six in-line needles (SURTRON SB). Several ex-vivo and in-vivo pig liver experiments and a first-phase clinical study allowed the realization of a prototype radiofrequency (RF) generator that works at 470 kHz, 150 watts maximum power delivered. The probe consists of six needle electrodes of 1.5 mm diameter, with 4.5 mm free space, 6.0 mm centre to centre, between each. We obtained a coagulation of 35 mm length and 12 mm width. The transection was performed with a common scalpel after coagulation of liver parenchyma. We observed good healing of the liver edge both in animal model and in ongoing pilot clinical study. Coagulation with SURTRON SB allows a feasible, easy and safe bloodless liver resection. This method is tolerated with no systemic complication or adverse reaction. This technique offers a method for a bloodless hepatic transection without the need for sutures, ties, staples or tissue glue.

Techniques for liver parenchymal transection: a meta-analysis of randomized controlled trials

BACKGROUND

Different techniques of liver parenchymal transection have been described, including the finger fracture, sharp dissection, clamp-crush methods and, more recently, the Cavitron ultrasonic surgical aspirator (CUSA), the hydrojet and the radiofrequency dissection sealer (RFDS). This review assesses the benefits and risks associated with the various techniques.

METHODS

Randomized clinical trials were identified from the Cochrane Library Trials Register, MEDLINE, EMBASE, Science Citation Index Expanded and reference lists. Odds ratio (ORs), mean difference (MDs) and standardized mean differences (SMDs) were calculated with 95% confidence intervals based on intention-to-treat analysis or available-case analysis.

RESULTS

We identified seven trials including a total of 556 patients. Blood transfusion requirements were lower with the clamp-crush technique than with the CUSA or hydrojet. The clamp-crush technique was quicker than the CUSA, hydrojet or RFDS. Infective complications and transection blood loss were greater with the RFDS than with the clamp-crush method. There was no significant difference between techniques in mortality, morbidity, liver dysfunction or intensive therapy unit and hospital stay.

CONCLUSIONS

The clamp-crush technique is more rapid and is associated with lower rates of blood loss and otherwise similar outcomes when compared with other methods of parenchymal transection. It represents the reference standard against which new methods may be compared.

Research and development of a new RF-assisted device for bloodless rapid transection of the liver: computational modeling and in vivo experiments

Background

Efficient and safe transection of biological tissue in liver surgery is strongly dependent on the ability to address both parenchymal division and hemostasis simultaneously. In addition to the conventional clamp crushing or finger fracture methods other techniques based on radiofrequency (RF) currents have been extensively employed to reduce intraoperative blood loss. In this paper we present our broad research plan for a new RF-assisted device for bloodless, rapid resection of the liver.

Methods

Our research plan includes computer modeling and in vivo studies. Computer modeling was based on the Finite Element Method (FEM) and allowed us to estimate the distribution of electrical power deposited in the tissue, along with assessing the effect of the characteristics of the device on the temperature profiles. Studies based on in vivo pig liver models provided a comparison of the performance of the new device with other techniques (saline-linked technology) currently employed in clinical practice. Finally, the plan includes a pilot clinical trial, in which both the new device and the accessory equipment are seen to comply with all safety requirements.

Results

The FEM results showed a high electrical gradient around the tip of the blade, responsible for the maximal increase of temperature at that point, where temperature reached 100°C in only 3.85 s. Other hot points with lower temperatures were located at the proximal edge of the device. Additional simulations with an electrically insulated blade produced more uniform and larger lesions (assessed as the 55°C isotherm) than the electrically conducting blade. The in vivo study, in turn, showed greater transection speed (3 ± 0 and 3 ± 1 cm²/min for the new device in the open and laparoscopic approaches respectively) and also lower blood loss (70 ± 74 and 26 ± 34 mL) during transection of the liver, as compared to saline-linked technology (2 ± 1 cm²/min with P = 0.002, and 527 ± 273 mL with P = 0.001).

Conclusion

A new RF-assisted device for bloodless, rapid liver resection was designed, built and tested. The results demonstrate the potential advantages of this device over others currently employed.

Techniques for liver parenchymal transection in liver resection

BACKGROUND

Blood loss during elective liver resection is one of the main factors affecting the surgical outcome. Different parenchymal transection techniques have been suggested to decrease blood loss.

OBJECTIVES

To assess the benefits and risks of the different techniques of parenchymal transection during liver resections.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded (March 2008).

SELECTION CRITERIA

We considered for inclusion all randomised clinical trials comparing different methods of parenchymal dissection irrespective of the method of vascular occlusion or any other measures used for lowering blood loss.

DATA COLLECTION AND ANALYSIS

Two authors identified the trials and extracted the data on the population characteristics, bias risk, mortality, morbidity, blood loss, transection speed, and hospital stay independently of each other. We calculated the odds ratio (OR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals based on 'interntion-to-treat analysis' or 'available case analysis' using RevMan 5.

MAIN RESULTS

We included seven trials randomising 556 patients. The comparisons include CUSA (cavitron ultrasound surgical aspirator) versus clamp-crush (two trials); radiofrequency dissecting sealer (RFDS) versus clamp-crush (two trials); sharp dissection versus clamp-crush technique (one trial); and hydrojet versus CUSA (one trial). One trial compared CUSA, RFDS, hydrojet, and clamp-crush technique. The infective complications and transection blood loss were greater in the RFDS than clamp-crush. There was no difference in the blood transfusion requirements, intensive therapy unit (ITU) stay, or hospital stay in this comparison. There was no significant differences in the mortality, morbidity, markers of liver parenchymal injury or liver dysfunction, ITU, or hospital stay in the other comparisons. The blood transfusion requirements were lower in the clamp-crush technique than CUSA and hydrojet. There was no difference in the transfusion requirements of clamp-crush technique and sharp dissection. Clamp-crush technique is quicker than CUSA, hydrojet, and RFDS. The transection speed of sharp dissection and clamp-crush technique was not compared. There was no clinically or statistically significant difference in the operating time between sharp dissection and clamp-crush techniques. Clamp-crush technique is two to six times cheaper than the other methods depending upon the number of surgeries performed each year.

AUTHORS' CONCLUSIONS

Clamp-crush technique is advocated as the method of choice in liver parenchymal transection because it avoids special equipment, whereas the newer methods do not seem to offer any benefit in decreasing the morbidity or transfusion requirement.

Monopolar floating ball versus bipolar forceps for hepatic resection: a prospective randomized clinical trial

BACKGROUND

Hepatic transection by Pean-clasia is the mainstream technique that can be used with different coagulators. Monopolar floating ball (MFB) is proposed for liver transection. Whether its value for liver transection is unclear, its efficiency as a coagulator only seems high. We compared in a prospective randomized study the standard Pean-clasia with bipolar forceps (BF) versus Pean-clasia with MFB in patients undergoing hepatic resection.

METHODS

Seventy-six patients scheduled for hepatectomy were randomized in two groups, according to the coagulator device: group A (MFB, n = 38) and group B (BF, n = 38). The two groups were homogeneous in terms of tumor presentation and background liver features. Blood loss, blood transfusions, transection time, number of ligatures, drain discharge, drain bilirubin levels at third, fifth, and seventh postoperative day, and postoperative morbidity and mortality were prospectively evaluated.

RESULTS

No significant differences between groups A and B were seen in terms of blood transfusions (11.5% versus 16.5%; p = 0.450), blood loss/cm(2) (mean 7.2 versus 7.6 ml; p = 0.450), transection time/cm(2) (mean 2.1 versus 2.3; p = 0.070), number of ligatures/cm(2) (mean 0.7 versus 0.7; p = 1), drain discharge (mean 55 versus 66.7 ml; p = 0.451), and drain bilirubin levels (mean 1.9 versus 2.1 mg/dl; p = 0.664). No mortality or major morbidity was recorded in both groups.

CONCLUSIONS

This study showed that association of Pean-clasia with MFB was safe and minimized the blood loss during hepatic resection. However, MFB did not offer significant benefits over BF, while its cost is not negligible.

A radiofrequency-assisted device for bloodless rapid transection of the liver: A comparative study in a pig liver model

BACKGROUND

Efficient and safe liver parenchymal transection is dependent on the ability to address both parenchymal division and hemostasis simultaneously. In this article we describe and compare with a saline-linked instrument a new radiofrequency (RF)-assisted device specifically designed for tissue thermocoagulation and division of the liver used on an in vivo pig liver model.

METHODS

In total, 20 partial hepatectomies were performed on pigs through laparotomy. Two groups were studied: group A (n=8) with hepatectomy performed using only the proposed RF-assisted device and group B (n=8) with hepatectomy performed using only a saline-linked device. Main outcome measures were: transection time, blood loss during transection, transection area, transection speed and blood loss per transection area. Secondary measures were: risk of biliary leakage, tissue coagulation depth and the need for hemostatic stitches. Tissue viability was evaluated in selected samples by staining of tissue NADH.

RESULTS

In group A both blood loss and blood loss per transection area were lower (p=0.001) than in group B (70+/-74 ml and 2+/-2 ml/cm(2) vs. 527+/-273 ml and 13+/-6 ml/cm(2), for groups A and B, respectively). An increase in mean transection speed when using the proposed device over the saline-linked device group was also demonstrated (3+/-0 and 2+/-1cm(2)/min for group A and B, respectively) (p=0.002). Tissue coagulation depth was greater (p=0.005) in group A than in group B (6+/-2 mm and 3+/-1 mm, for groups A and B, respectively). Neither macroscopic nor microscopic differences were encountered in transection surfaces between both groups.

CONCLUSIONS

The proposed RF-assisted device was shown to address parenchymal division and hemostasis simultaneously, with less blood loss and faster transection time than saline-linked technology in this experimental model.