Effects of different pressure levels of CO2 pneumoperitoneum on liver regeneration after liver resection in a rat model

Impact of laparoscopic liver resection on liver regeneration

BACKGROUND

Liver regeneration after liver resection plays an important role in preventing posthepatectomy liver failure. In this study, we aimed to evaluate and compare the impact of laparoscopic liver resection (LLR) and open liver resection (OLR) on liver regeneration.

METHODS

Patients who underwent curative anatomical liver resection for hepatocellular carcinoma, cholangiocellular carcinoma, and colorectal liver metastases at our institution between January 2010 and December 2018 were included in this study. The patients were divided into the OLR and LLR groups. Preoperative liver volume (PLV), future remnant liver volume, resected liver volume (RLV), liver volume at 1 month after the surgery, and liver volume at 6 months after the surgery were calculated. The liver regeneration rate was defined as the increase in the rate of RLV, and the liver recovery rate was defined as the rate of return to the PLV.

RESULTS

The study included 72 patients. Among them, 43 were included in the OLR group and 29 were included in the LLR group. No differences were observed in the baseline characteristics and surgical procedures between the two groups. Moreover, no significant difference was observed in the liver regeneration rate at 1 month after the surgery (OLR vs. LLR: 68.9% vs. 69.0%, p = 0.875) and at 6 months after the surgery (91.8% vs. 93.2%, p = 0.995). Furthermore, the liver recovery rates were not significantly different between the two groups at 1 month after the surgery (90.3% vs. 90.6%, p = 0.893) and at 6 months after the surgery (96.9% vs. 98.8%, p = 0.986).

CONCLUSION

Liver regeneration after liver resection is not affected by the type of surgical procedure and both laparoscopic and open procedures yield similar regeneration and recovery rates.

Assessment for the minimal invasiveness of laparoscopic liver resection by interleukin-6 and thrombospondin-1

BACKGROUND

Laparoscopic surgery has been introduced as a minimally invasive technique for the treatment of various field. However, there are few reports that have scientifically investigated the minimally invasive nature of laparoscopic liver resection (LLR).

AIM

To investigate whether LLR is scientifically less invasive than open liver resection.

METHODS

During December 2011 to April 2015, blood samples were obtained from 30 patients who treated with laparoscopic (n = 10, 33%) or open (n = 20, 67%) partial liver resection for liver tumor. The levels of serum interleukin-6 (IL-6) and plasma thrombospondin-1 (TSP-1) were measured using ELISA kit at four time points including preoperative, immediate after operation, postoperative day 1 (POD1) and POD3. Then, we investigated the impact of the operative approaches during partial hepatectomy on the clinical time course including IL-6 and TSP-1.

RESULTS

Serum level of IL-6 on POD1 in laparoscopic hepatectomy was significantly lower than those in open hepatectomy (8.7 vs 30.3 pg/mL, respectively) (P = 0.003). Plasma level of TSP-1 on POD3 in laparoscopic hepatectomy was significantly higher than those in open hepatectomy (1704.0 vs 548.3 ng/mL, respectively) (P = 0.009), and have already recovered to preoperative level in laparoscopic approach. In patients with higher IL-6 Levels on POD1, plasma level of TSP-1 on POD3 was significantly lower than those in patients with lower IL-6 Levels on POD1. Multivariate analysis showed that open approach was the only independent factor related to higher level of IL-6 on POD1 [odds ratio (OR), 7.48; 95% confidence interval (CI): 1.28-63.3; P = 0.02]. Furthermore, the higher level of serum IL-6 on POD1 was significantly associated with lower level of plasm TSP-1 on POD3 (OR, 5.32; 95%CI: 1.08-32.2; P = 0.04) in multivariate analysis.

CONCLUSION

In partial hepatectomy, laparoscopic approach might be minimally invasive surgery with less IL-6 production compared to open approach.

Recent developments in in vitro and in vivo models for improved translation of preclinical pharmacokinetics and pharmacodynamics data

Improved pharmacokinetics/pharmacodynamics (PK/PD) prediction in the early stages of drug development is essential to inform lead optimization strategies and reduce attrition rates. Recently, there have been significant advancements in the development of new in vitro and in vivo strategies to better characterize pharmacokinetic properties and efficacy of drug leads. Herein, we review advances in experimental and mathematical models for clearance predictions, advancements in developing novel tools to capture slowly metabolized drugs, in vivo model developments to capture human etiology for supporting drug development, limitations and gaps in these efforts, and a perspective on the future in the field.

Effect of laparoscopic liver resection versus the open technique on hepatocyte regenerating activity in the rat

BACKGROUND

Laparoscopic liver resection offers a safe and feasible option primarily for the excision of hepatic neoplasms. Timely recovery of liver volume is a key factor for improving prognosis and post-operative mortality of patients undergone liver resection. The aim of the present study was to compare liver regeneration after laparoscopic over open partial hepatectomy.

METHODS

Wistar rats were subjected to laparoscopic 70% hepatectomy (group LAP-HEP), open 70% hepatectomy (group HEP), sham operation (group Sham) or no intervention (group Control). At various timepoints following operation (1 h-2 weeks), the liver was excised to assess relative liver weight, thiobarbituric acid reactive substances (TBARS) levels, mitotic activity, tissue expression of Nuclear Factor-κB (NFκB), Intercellular Adhesion Molecule-1 (ICAM-1) and Vascular Cell Adhesion Molecule-1 (VCAM-1) and the histopathologic profile.

RESULTS

No differences were seen in relative liver weight between hepatectomy groups. Mitotic index was increased in all operative study groups, being higher in group LAP-HEP than in group HEP. TBARS levels were higher in group LAP-HEP compared to group HEP. NFκB and VCAM-1 tissue expression scores were increased in all operative study groups with VCAM-1 being higher in group HEP, while ICAM-1 was overexpressed only in hepatectomy groups. Mild histopathologic lesions were noted in hepatectomy groups with the histopathologic score being higher in group HEP (24 h).

CONCLUSIONS

Laparoscopic liver resection enhanced hepatocyte mitotic activity which was accompanied by mild oxidative stress and a less pronounced local inflammatory response and tissue injury to that of the open technique.

Pharmacokinetic and toxicodynamic evaluation of 5-fluorouracil administration after major hepatectomy in a rat model

BACKGROUND

Chemotherapy after hepatectomy for colorectal liver metastasis has not been established, due to the toxic side effects, which are likely related to impaired drug clearance during liver regeneration. We investigated the pharmacokinetic and toxicodynamic evaluation of 5-fluorouracil (5-FU) during liver regeneration after major hepatectomy in a rat model.

METHODS

Thirty-six male Wistar rats were divided into control (C), control with chemotherapy (CC), hepatectomy (H), and hepatectomy with chemotherapy (HC) groups. The CC and HC groups were administered 5-FU for 4 days. Plasma 5-FU, liver weight, and liver dihydropyrimidine dehydrogenase (DPD) were measured. The ileal villous height was measured to determine adverse effects.

RESULTS

The area under the curve and maximum plasma concentration of 5-FU increased by up to 51% and 32%, respectively, in the HC group compared to the CC group. The liver regeneration rate was significantly lower in the HC group than in the H group (67.3 ± 7.4 vs 33.0 ± 5.7%, p < 0.001). The HC group had a significantly lower liver DPD than the CC group (4.4 ± 1.1 mg vs 6.9 ± 1.1 mg, p < 0.01). The HC group had a significantly lower ileal villous height than the CC group (253 ± 40 μm vs. 318 ± 36 μm, p < 0.05).

CONCLUSIONS

Reduction of the total liver DPD following major hepatectomy caused increased plasma 5-FU levels and 5-FU-associated toxicity.

Use of robotics in liver donor right hepatectomy

Liver transplantation is the best solution for end stage liver disease, and has been widely accepted and rapidly developed in the past decades. Along with the improved outcomes of liver transplantation, living-related donor transplantation has been conducted to overcome the shortage of the deceased donor. The most important aspects of the living-related liver transplantation are donor safety and fast recovery after graft procurement. Meanwhile, the rapid progress of minimally invasive surgery (MIS) in general surgery has generated heated debate regarding the appropriateness of MIS in living-related donor graft hepatectomy. Technical innovations and instrument enhancements have been allowing recruitment of more potential candidates through smaller wounds and better surgical experience. Although MIS has been documented with safety and feasibility in complex liver surgery, the progress is slow in regard to the application of MIS in donor graft hepatectomy. Pioneer surgeons have devoted themselves to develop the pure MIS approach for the liver donor surgery, but the steep learning curve for pure MIS major hepatectomy remains a major barrier for wide adoption. The introduction of robotic system may lower the barrier for entry for practice into MIS donor hepatectomy.

The effects of enoxaparin on the liver in experimental pneumoperitoneum model

PURPOSE:

To investigate the potential protective effects of enoxaparin against the adverse events of carbon dioxide (CO2) pneumoperitoneum.

METHODS:

Thirty four rats were divided into three groups: Group 1 (sham) underwent insertion of Veress needle into the abdomen and 90 min of anesthesia with no gas insufflation. The animals in control and enoxaparin groups were subjected to 90 min of 14 mmHg CO2 pneumoperitoneum. Enoxaparin (100 u/kg) was administered subcutaneously to the rats in enoxaparin group one hour before the operation. After 90 min of pneumoperitoneum, the rats were allowed for reperfusion through 60 min. Blood and liver samples were obtained for biochemical and histopathological examination.

RESULTS:

Treatment with enoxaparin decreased the histopathological abnormalities when compared with the control group. The highest levels of oxidative stress parameters were found in control group. The use of enoxaparin decreased the levels of all oxidative stress parameters, but the difference between the control and enoxaparin groups was not statistically significant.

CONCLUSION:

Enoxaparin ameliorated the harmful effects of high pressure CO2 pneumoperitoneum on the liver.

Robotic liver donor right hepatectomy: A pure, minimally invasive approach

Right hepatectomy for a living liver donor via a pure minimally invasive approach is a challenging procedure and only a few cases have been reported. Between May 2013 and August 2015, 13 patients underwent robotic living donor right hepatectomy in our institute, and 54 patients received open surgery. In this series, no conversion was conducted for robotic donor right hepatectomy. The 2 groups shared similar blood loss (169 versus 146 mL), complication rates (7.7% versus 9.3%), and recovery of donor liver function (peak alanine aminotransferase, 269 versus 252 IU/mL). The robotic group needed longer operation time (596 versus 383 minutes) but less postoperative patient-controlled analgesia (0.58 versus 0.84 ng/kg) and a shorter period before returning to work/school (52.9 versus 100.0 days) and sex (100.0 versus 156.0 days). For recipient outcomes regarding the donor procedure, the robotic group shared similar experiences in early allograft dysfunction, complications, and 1-year recipient liver function with the open group. With respect to documented benefits of minimally invasive left-sided liver donor procedure, the development of right donor hepatectomy is slow. In conclusion, with substantial improvements in patient recovery after the minimally invasive approach, the robotic platform would be a big step toward completing pure minimally invasive liver donor surgery. Liver Transplantation 22 1509-1518 2016 AASLD.

Percutaneous internal ring suturing is a safe and effective method for the minimal invasive treatment of pediatric inguinal hernia: Experience with 250 cases

BACKGROUND/PURPOSE

Percutaneous internal ring suturing (PIRS) is a minimally invasive method for repair of pediatric inguinal hernia. In this study we report our experience with PIRS.

METHODS

All children >10kg presenting to our institute between June 2013 and March 2015 with a diagnosis of indirect inguinal hernia or communicating hydrocele underwent laparoscopic repair using PIRS technique. Patients' gender, age at surgery, side of inguinal hernia/communicating hydrocele at diagnosis, peroperative findings, surgical and anesthesia times plus follow-up findings were collected.

RESULTS

Two-hundred thirteen patients underwent 250 procedures. Inguinal hernia or communicating hydrocele was diagnosed on the right side in 113 (53.1%), the left side in 75 (35.2%) and bilaterally in 25 patients (11.7%). Contralateral hernia was found in 35 patients (16.4%). Mean surgery time was 14.3min for unilateral and 20.4min for bilateral PIRS, and mean anesthesia time was 33.6min for unilateral and 39.1min for bilateral PIRS. Average follow-up time was 9.6months. Recurrence was seen in 3 (1.4%) and complications in 6 patients (2.8%).

CONCLUSION

PIRS is a simple, safe and effective method for the treatment of inguinal hernia and communicating hydrocele in children.