Laparoscopic parenchymal division of the liver in a porcine model: comparison of the efficacy and safety of three different techniques

Laparoscopic liver resection with "ultrasonic scalpel mimic CUSA" technique

BACKGROUND

Liver parenchymal transection is the most critical step for laparoscopic liver resection (LLR). Ultrasonic scalpel (Harmonic) is a common used energy instrument in LLR; however, it is only recommended for superficial layer transection and the Cavitron Ultrasonic Surgical Aspirator (CUSA) is recommended for deep layer dissection. We herein introduce the "Harmonic mimic CUSA" technique for LLR.

METHODS

We retrospectively reviewed the medical records of the patients who underwent LLR using CUSA or the "Harmonic mimic CUSA" for parenchymal transection between July 2018 and October 2020 at West China Hospital of Sichuan University. Observation indicators included general demographic information, operative time, intraoperative blood loss, blood transfusion volume, complication rate, hospital stay, and the costs. Perioperative data was compared between the two groups by propensity score matching analysis (PSM).

RESULTS

A total of 298 patients, including 192 in Harmonic group and 106 in CUSA group, were enrolled in this study. After a 1:1 PSM, 99 patients using "Harmonic mimic CUSA" were matched with 99 patients via CUSA for parenchymal transection in LLRs. The Harmonic group had significantly less intraoperative blood loss (mean, 150 ml vs. 250 ml, P < 0.001), shorter operative time (mean 170 min vs. 250 min, P < 0.001) and less costs (mean 6723$ vs. 8307$, P < 0.001). The conversion to laparotomy, length of postoperative hospital stay, complications were comparable between the two groups. There perioperative mortality was nil.

CONCLUSION

The "Harmonic mimic CUSA" technique is safe, simple and feasible for LLR, which may be an alternative to CUSA for LLR.

Gas embolism under standard versus low pneumoperitoneum pressure during laparoscopic liver resection (GASES): study protocol for a randomized controlled trial

Background

Gas embolism induced by CO₂ pneumoperitoneum is commonly identified as a risk factor for morbidity, especially cardiopulmonary morbidity, after laparoscopic liver resection (LLR) in adults. Increasing pneumoperitoneum pressure (PP) contributes to gas accumulation following laparoscopy. However, few studies have examined the effects of PP in the context of LLR. In LLR, the PP-central venous pressure (CVP) gradient is increased due to hepatic vein rupture, hepatic sinusoid exposure, and low CVP management, which together increase the risk of CO₂ embolization. The aim of this study is to primarily determine the role of low PP (10 mmHg) on the incidence of severe gas embolism.

Methods

Adult participants (n = 140) undergoing elective LLR will be allocated to either a standard (15 mmHg) or low (10 mmHg) PP group. Anesthesia management, postoperative care, and other processes will be performed similarly in both groups. The occurrence of severe gas embolism, which is defined as gas embolism ≥ grade 3 according to the Schmandra microbubble method, will be detected by transesophageal echocardiography (TEE) and recorded as the primary outcome. The subjects will be followed up until discharge and followed up by telephone 1 and 3 months after surgery. Postoperative outcomes, such as the Post-Operative Quality of Recovery Scale, pain severity, and adverse events, will be assessed. Serum cardiac markers and inflammatory factors will also be assessed during the study period. The correlation between intraoperative inferior vena cava-collapsibility index (IVC-CI) under TEE and central venous pressure (CVP) will also be explored.

Discussion

This study is the first prospective randomized clinical trial to determine the effect of low versus standard PP on gas embolism using TEE during elective LLR. These findings will provide scientific and clinical evidence of the role of PP.

Trial status

Protocol version: version 1 of 21-08-2020

Trial registration

ChiCTR2000036396 (http://www.chictr.org.cn). Registered on 22 August 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05678-8.

Laparoscopic left hemihepatectomy combined with right lateral hepatic lobectomy in pigs: surgical approach and comparative study of the inflammatory response versus open surgery

This study describes a left hemihepatectomy combined with a right lateral hepatic lobectomy. It compares the inflammatory response associated with laparoscopic hepatectomy (LH group, n = 7) with conventional open hepatectomy (OH group, n = 7). Blood was collected before surgery as well as 1, 2, 3, 5, and 7 days after surgery to determine the white blood cell count and levels of serum cortisol (COR), interleukin-6 (IL-6), and C-reactive protein (CRP). The left hemi-hepatectomy combined with a right lateral hepatic lobectomy was completed in miniature pigs. The average operative time was 139.00 ± 9.07 min, which was longer than that in the OH group (121.67 ± 3.02 min). The length of surgical incision associated with the OH group was 17.93 ± 1.09 cm, significantly longer than that related to the LH group (5.10 ± 0.17 cm). The estimated mean blood loss in the LH group was 136.43 ± 63.24 mL, which was significantly lower than that in the OH group. No severe complications (e.g., massive bleeding, bile leakage, and air embolism) were reported. The CRP levels, COR, and IL-6, increased significantly in the OH group and then slowly returned to their preoperative levels. A postoperative laparoscopic exploration revealed that the incised portion of the liver adhered to the omentum, but no additional abnormalities were observed. These findings indicate that a 4-trocar method for laparoscopic left hemihepatectomy combined with a right lateral hepatic lobectomy is safe and feasible. The inflammatory response for those receiving LH are lower than that for those receiving OH. This porcine model can be used as a research analog for liver disease and regeneration.

Randomized clinical trial comparing the effects of sevoflurane and propofol on carbon dioxide embolism during pneumoperitoneum in laparoscopic hepatectomy

Laparoscopic hepatectomy carries a high risk of gas embolism due to the extensive hepatic transection plane and large hepatic vena cava. Here, we compared the influence of inhaled and intravenous anesthetics on gas embolism during laparoscopic hepatectomy. Fifty patients undergoing laparoscopic hepatectomy were divided into two groups to receive sevoflurane anesthesia (group S, n = 25) or intravenous propofol anesthesia (group p, n = 25). During the operation, gas emboli were detected by transesophageal echocardiography and graded according to their size. Venous CO₂ emboli were detected in all patients, and the embolism grades did not differ between the two groups. However, the mean embolism episode duration was longer in group S than group P (51.24±23.59 vs. 34.00±17.13 sec, p < 0.05). At the point of the most severe gas embolism, the PT_CO2 was higher in group S than group p (44.00±4.47 vs. 41.36±2.77 mmHg, p < 0.05), while the PO₂/FiO₂ (450.52±54.08 vs. 503.80±63.18, p < 0.05) and pH values (7.35±0.05 vs. 7.38±0.02, p < 0.05) were lower in group S than group P. Patients with a history of abdominal surgery or liver cirrhosis had higher gas embolism grades. Thus volatile anesthetics may lengthen the duration of embolism episodes and worsen hemodynamics and pulmonary blood gas exchange during surgery.

Significance of a soft-coagulation system with monopolar electrode for hepatectomy: A retrospective two-institution study by propensity analysis

BACKGROUND

The VIO soft-coagulation system (VIO) with a monopolar electrode is a novel hemostatic device that provides hemostasis by superficial contact at the bleeding site without carbonization. Because heat injury remains a concern, surgical records and postoperative liver dysfunction were retrospectively evaluated in a cohort study.

METHODS

Between September 2010 and March 2016, 322 patients underwent hepatectomy in which hemostatic devices were used at two institutions. Surgical results with use of VIO at one institute (VIO group) were compared with those without use of VIO at a second institute (control group), and propensity analysis was performed.

RESULTS

In limited resection and segmentectomy or sectionectomy performed in the VIO group, the prevalence of liver cirrhosis was significantly higher and the operation time was significantly longer in comparison with the control group (p < 0.05). In all hepatectomies, postoperative levels of total bilirubin and aspartate or alanine transaminase tended to be increased and prothrombin activity tended to be lower in the VIO group in comparison with the control group (p < 0.05). The prevalence of hepatic failure in the VIO group was significantly higher in comparison with that in the control group (p < 0.05). In cases of segmentectomy or sectionectomy, blood loss was significantly increased in the VIO group in comparison with that in the control group (p < 0.05) Propensity score matching showed that although the surgical records and outcomes were not significantly different between the groups, postoperative liver dysfunction was significant in the VIO group in comparison with the control group (p < 0.05).

CONCLUSIONS

Mild postoperative hepatic thermal injury with VIO was confirmed, and therefore, surgeons should take care when using the VIO system to make frequent wide resected cuts on the surface of the liver.

What is the best technique in parenchymal transection in laparoscopic liver resection? Comprehensive review for the clinical question on the 2nd International Consensus Conference on Laparoscopic Liver Resection

The continuing evolution of technique and devices used in laparoscopic liver resection (LLR) has allowed successful application of this minimally invasive surgery for the treatment of liver disease. However, the type of instruments by energy sources and technique used vary among each institution. We reviewed the literature to seek the best technique for parenchymal transection, which was proposed as one of the important clinical question in the 2nd International Consensus Conference on LLR held on October 2014. While publications have described transection techniques used in LLR from 1991 to June 2014, it is difficult to specify the best technique and device for laparoscopic hepatic parenchymal transection, owing to a lack of randomized trials with only a small number of comparative studies. However, it is clear that instruments should be used in combination with others based on their functions and the depth of liver resection. Most authors have reported using staplers to secure and divide major vessels. Preparation for prevention of unexpected hemorrhaging particularly in liver cirrhosis, the Pringle's maneuver and prompt technique for hemostasis should be performed. We conclude that hepatobiliary surgeons should select techniques based on their familiarity with a concrete understanding of instruments and individualize to the procedure of LLR.

High-frequency jet ventilation shortened the duration of gas embolization during laparoscopic liver resection in a porcine model

BACKGROUND

Positive pressure mechanical ventilation causes rhythmic changes in thoracic pressure and central blood flow. If entrainment occurs, it could be easier for carbon dioxide to enter through a wounded vein during laparoscopic liver lobe resection (LLR). High-frequency jet ventilation (HFJV) is a ventilating method that does not cause pronounced pressure or blood flow changes. This study aimed to investigate whether HFJV could influence the frequency, severity, or duration of gas embolism (GE) during LLR.

METHODS

Twenty-four anaesthetized piglets underwent lobe resection and were randomly assigned to either normal frequency ventilation (NFV) or HFJV (n=12 per group). During resection, a standardized injury to the left hepatic vein was created to increase the risk of GE. Haemodynamic and respiratory variables were monitored. Online blood gas monitoring and transoesophageal echocardiography were used. GE occurrence and severity were graded as 0 (none), 1 (minor), or 2 (major), depending on the echocardiography results.

RESULTS

GE duration was shorter in the HFJV group (P=0.008). However, no differences were found between the two groups in the frequency or severity of embolism. Incidence of Grade 2 embolism was less than that found in previous studies and physiological responses to embolism were variable.

CONCLUSION

HFJV shortened the mean duration of GE during LLR and was a feasible ventilation method during the procedure. Individual physiological responses to GE were unpredictable.

Usefulness of vessel-sealing devices combined with crush clamping method for hepatectomy: a retrospective cohort study

BACKGROUND

Blood loss during resection of the hepatic parenchyma in hepatectomy can be minimized using vessel-sealing (VS) devices. Some sealing devices were retrospectively compared to evaluate the efficacy of each device for controlling blood loss, transection time and postoperative complications in hepatectomy as a cohort study.

METHODS

Between 2005 and September 2012, hepatectomy was underwent in 150 patients using one of three types of LigaSure™ (Dolphin Tip Laparoscopic Instrument, Precise or Small Jaw) or the Harmonic Focus or Ace ultrasonic dissecting sealer. Results were compared to crush-clamping alone as the control method by the historical study (n = 81).

RESULTS

Irrespective of the vessel-sealing device used for underlying chronic hepatitis, blood loss, blood transfusion rate, operating time and transection time were significantly reduced in the VS group compared with controls (p < 0.05). Rates of postoperative bile leakage and intra-abdominal abscess formation were significantly lower in the VS group than in controls (p < 0.05). Comparing devices, LigaSure Small Jaw and Harmonic Focus showed lower blood loss, shorter transection time and reduced rates of post-hepatectomy complications, in turn resulting in shorter hospital stays (p < 0.05). Tendencies toward uncontrolled ascites and bile leakage were only concern with the use of Harmonic Focus. Satisfactory surgical results were achieved using the sealing device for laparoscopic hepatectomy.

CONCLUSIONS

The use of energy sealing devices improves surgical results and avoids hepatectomy-related complications. Adequate use of vessel sealers is necessary for safe and rapid completion of hepatic resection.

Elevated PEEP without effect upon gas embolism frequency or severity in experimental laparoscopic liver resection

BACKGROUND

Carbon dioxide (CO(2)) embolism is a potential complication in laparoscopic liver surgery. Gas embolism (GE) is thought to occur when central venous pressure (CVP) is lower than the intra-abdominal pressure (IAP). This study aimed to investigate whether an increased CVP due to induction of PEEP could influence the frequency and severity of GE during laparoscopic liver resection.

METHODS

Twenty anaesthetized piglets underwent laparoscopic left liver lobe resection and were randomly assigned to either 5 or 15 cm H(2)O PEEP (n=10 per group). During resection, a standardized injury to the left hepatic vein [venous cut (VC)] was created to increase the risk of GE. Haemodynamic and respiratory variables were monitored, and online arterial blood gas monitoring and transoesophageal echocardiography (TOE) were used. The occurrence and severity of embolism was graded as 0 (none), 1 (minor), or 2 (major), depending on the TOE results.

RESULTS

No differences were found between the two groups regarding the frequency or severity of GE, during either the VC (P=0.65) or the rest of the surgery (P=0.24). GE occurred irrespective of the CVP-IAP gradient.

CONCLUSIONS

Mechanisms other than the CVP-IAP gradient seemed during laparoscopic liver surgery to contribute to the formation of CO(2) embolism. This is of clinical importance to the anaesthetists.

Gas embolism during laparoscopic liver resection in a pig model: frequency and severity

BACKGROUND

Laparoscopic liver surgery is evolving rapidly. Carbon dioxide embolism is a potential complication. The aim of this work was to study the frequency and severity of gas embolism (GE) during laparoscopic liver lobe resection in a pig model and the resulting cardiovascular and respiratory changes.

METHODS

Fifteen anaesthetized piglets underwent laparoscopic left liver lobe resection. Haemodynamic and respiratory variables were monitored, including systemic and pulmonary arterial pressures, end-tidal CO2, and pulmonary dead space. Online blood gas monitoring and a transoesophageal echocardiography (TOE) were used. GE was graded semi-quantitatively as grade 0 (none), grade 1 (minor), or grade 2 (major), depending on the TOE results.

RESULTS

In 10 of 15 piglets, GE occurred. In total, 33 separate episodes of GE were recorded. All 13 episodes of grade 2 and three of grade 1 were serious enough to cause mainly respiratory, but also haemodynamic effects. Mostly, grade 1 GE caused only minor respiratory or haemodynamic changes. Most variables were affected during grade 2 GE; the most important were Pa(o(2)), Pa(co(2)), end-tidal CO2, Vd/Vt, and mean pulmonary arterial pressure.

CONCLUSIONS

GE occurred frequently during laparoscopic liver resection in this experimental study. Approximately half of the embolisms were serious enough to cause respiratory or haemodynamic disturbances or both. Pending further human studies, a combination of several monitoring techniques, with narrow limits for the alarm settings, will ensure correct interpretation of the complex physiological response to GE and reveal it early enough to alert the anaesthetist and the surgeon to the ongoing problem.

Initial results of MR-guided liver resection in a high-field open MRI

BACKGROUND

The goal of this study was to evaluate high-field open magnetic resonance imaging (MRI) for intraoperative real-time imaging during hand-assisted laparoscopic liver resection. MR guidance has several advantages compared to ultrasound and may represent a future technique for abdominal surgery. Various MRI-safe and -compatible instruments were developed, tested, and applied to realize minimally invasive liver surgery under MR guidance. As proof of the concept, liver resection was performed in a porcine model.

METHODS

All procedures were conducted in a 1.0-T open MRI unit. Imaging quality and surgical results were documented during three cadaveric and two live animal procedures. A nonferromagnetic hand port was used for manual access and the liver tissue was dissected using a Nd:YAG laser.

RESULTS

The intervention time ranged from 126 to 145 min, with a dissection time from 11 to 15 min. Both live animals survived the intervention with a blood loss of 250 and 170 ml and a specimen weight of 138 and 177 g. A dynamic T2W fast spin-echo sequence allowed real-time imaging (1.5 s/image) with good delineation of major and small hepatic vessels. The newly developed MR-compatible instruments and camera system caused only minor interferences and artifacts of the MR image.

CONCLUSION

MR-guided liver resection is feasible and provides additional image information to the surgeon. We conclude that MR-guided laparoscopic liver resection improves the anatomical orientation and may increase the safety of future minimally invasive liver surgery.

Laparoscopic left lobe liver resection in a porcine model: a study of the efficacy and safety of different surgical techniques

INTRODUCTION

Laparoscopic liver surgery is evolving and the best technique for dividing the liver parenchyma is currently under debate. The aim of this study was to study different techniques during a full laparoscopic lobe resection, and determine the efficacy and risks of bleeding and gas embolism.

METHODS

Sixteen pigs were randomized to two groups: group US underwent an operation with Ultracision shears (AutoSonix) and ultrasonic dissector (CUSA) and group VS with a vessel sealing system (Ligasure) and ultrasonic dissector. A left lobe resection was performed. Transesophageal endoscopic echocardiography (TEE) was used to detect gas emboli in the right side of the heart and pulmonary artery. The operations and TEE were recorded for later assessment.

RESULTS

Compared with group VS, group US exhibited significantly more intraoperative bleeding (p = 0.02), a trend towards a longer operation time (p = 0.08), and a trend towards more embolization for grade I emboli. In total, 10 of 15 animals had emboli during the operation.

CONCLUSIONS

This study showed that a laparoscopic left lobe resection can be performed with a combination of AutoSonix and CUSA as well as with Ligasure and CUSA instrumentation. In our hands, less bleeding was incurred with Ligasure than with AutoSonix.

The association between central venous pressure, pneumoperitoneum, and venous carbon dioxide embolism in laparoscopic hepatectomy

BACKGROUND

Laparoscopic hepatectomy (LH) is increasingly used. However, the safety and outcomes of LH have yet to be elucidated. The risk of venous gas embolism is increased during liver parenchymal transection. This risk may be increased with positive pressure carbon dioxide (CO(2)) pneumoperitoneum (PP). This may be exacerbated further when low central venous pressure (CVP) anesthesia is used to minimize hemorrhage during liver resection.

METHODS

To determine the risk of CO(2) venous embolism, hand-assisted laparoscopic left hepatic lobectomy was performed for 26 domestic pigs. They were divided into three groups involving, respectively, positive gradient (normal-pressure PP of 12-14 mmHg and low CVP of 5-7 mmHg), negative gradient (low-pressure PP of 7-8 mmHg and normal CVP of 10-12 mmHg), and neutral gradient (normal-pressure PP and normal CVP or low-pressure PP and low CVP). Transesophageal echocardiography (TEE) was used intraoperatively to assess the presence of emboli in the suprahepatic vena cava and the right side of the heart. The TEE was recorded and analyzed by blinded observers. Carbon dioxide embolism also was monitored using end-tidal CO(2) and compared with TEE.

RESULTS

Carbon dioxide embolism was demonstrated in 19 of the 26 cases. The majority of gas emboli were small gas bubbles associated with dissection of the major hepatic veins. No statistically significant difference in the occurrence of gas emboli was observed between the groups. Of the 19 animals, 18 experienced no significant hemodynamic changes. One pig in the positive gradient group experienced hypotension in relation to gas embolism. The effects were only transient and did not preclude safe completion of the operation.

CONCLUSIONS

Carbon dioxide embolism during LH occurs frequently. Clinically, this finding appears to be nominal, but care must be taken when dissection around large veins is performed, and awareness by the surgical and anesthesiology teams of potential venous air embolism is essential. Further evaluation of this phenomenon is required.

Laparoscopic liver resection using a bipolar vessel-sealing device: LigaSure

Achieving safe outcomes when performing laparoscopic liver surgery requires that the surgical team be expert in the techniques of liver surgery and in the application of appropriate technologies and devices. No other device is capable of effectively providing hemostasis, control of bile duct branches, and dividing parenchyma in every circumstance encountered during major hepatic resections. Therefore, liver surgeons use a variety of surgical technologies and instruments based on their judgment and experience and the individual nature of the operative procedure. Vessel-sealing technology has established itself as useful in liver surgery, for both open and laparoscopic cases. This paper reviews experience with a bipolar, vessel-sealing device (LigaSure, ValleyLab, Inc., Boulder, Colorado) and its application to laparoscopic liver surgery.