Experience with more than 500 minimally invasive hepatic procedures. Ann Surg. 2008;248:475-486. [PMID: 18791368 DOI: 10.1097/sla.0b013e318185e647]

The impact of Kirsten rat sarcoma (KRAS) status on local tumor progression after surgical ablation of colorectal liver metastases

BACKGROUND

Kirsten rat sarcoma mutation was reported to adversely affect local tumor control after percutaneous ablation of colorectal liver metastasis. Nevertheless, the effect of Kirsten rat sarcoma mutation on surgical ablation has not been investigated in the literature. The aim of this study is to analyze the impact of Kirsten rat sarcoma mutation on local recurrence after surgical ablation of colorectal liver metastasis.

METHODS

This was an institutional review board-approved study of patients who underwent surgical ablation of colorectal liver metastasis between 2005 and 2023 at a single center and underwent Kirsten rat sarcoma testing with ≥1 year follow-up. Local recurrence was analyzed using univariate Kaplan-Meier and multivariate Cox hazard models.

RESULTS

A total of 163 patients with 424 lesions fulfilled inclusion criteria. Fifty (30.7%) patients received radiofrequency ablation and 113 (69.3%) patients received microwave ablation. Fifty-seven patients (32.2%) with 177 lesions were found to have a Kirsten rat sarcoma mutation. Patients with Kirsten rat sarcoma mutation had a larger number of tumors, percentage of posteriorly located tumors, and tumor burden score compared with those with wild-type Kirsten rat sarcoma. Nevertheless, there was no difference between the groups regarding local recurrence per lesion (15% vs 17%, respectively, P = not significant). Independent predictors of local recurrence included tumor size, ablation margin, and blood vessel proximity for microwave ablation compared with tumor size and ablation margin for microwave ablation.

CONCLUSION

There was no effect of Kirsten rat sarcoma mutations on local recurrence after surgical radiofrequency ablation or microwave ablation of colorectal liver metastasis in this study. Tumor size and ablation margin remained as independent predictors.

Factors Associated with and Impact of Open Conversion in Laparoscopic and Robotic Minor Liver Resections: An International Multicenter Study of 10,541 Patients

INTRODUCTION

Despite the increasing widespread adoption and experience in minimally invasive liver resections (MILR), open conversion occurs not uncommonly even with minor resections and as been reported to be associated with inferior outcomes. We aimed to identify risk factors for and outcomes of open conversion in patients undergoing minor hepatectomies. We also studied the impact of approach (laparoscopic or robotic) on outcomes.

METHODS

This is a post-hoc analysis of 20,019 patients who underwent RLR and LLR across 50 international centers between 2004-2020. Risk factors for and perioperative outcomes of open conversion were analysed. Multivariate and propensity score-matched analysis were performed to control for confounding factors.

RESULTS

Finally, 10,541 patients undergoing either laparoscopic (LLR; 89.1%) or robotic (RLR; 10.9%) minor liver resections (wedge resections, segmentectomies) were included. Multivariate analysis identified LLR, earlier period of MILR, malignant pathology, cirrhosis, portal hypertension, previous abdominal surgery, larger tumor size, and posterosuperior location as significant independent predictors of open conversion. The most common reason for conversion was technical issues (44.7%), followed by bleeding (27.2%), and oncological reasons (22.3%). After propensity score matching (PSM) of baseline characteristics, patients requiring open conversion had poorer outcomes compared with successful MILR cases as evidenced by longer operative times, more blood loss, higher requirement for perioperative transfusion, longer duration of hospitalization and higher morbidity, reoperation, and 90-day mortality rates.

CONCLUSIONS

Multiple risk factors were associated with conversion of MILR even for minor hepatectomies, and open conversion was associated with significantly poorer perioperative outcomes.

Clinical feasibility of laparoscopic left lateral segment liver resection with magnetic anchor technique: The first clinical study from China

BACKGROUND

Magnetic anchor technique (MAT) has been applied in laparoscopic cholecystectomy and laparoscopic appendectomy, but has not been reported in laparoscopic partial hepatectomy.

AIM

To evaluate the feasibility of the MAT in laparoscopic left lateral segment liver resection.

METHODS

Retrospective analysis was conducted on the clinical data of eight patients who underwent laparoscopic left lateral segment liver resection assisted by MAT in our department from July 2020 to November 2021. The Y-Z magnetic anchor devices (Y-Z MADs) was independently designed and developed by the author of this paper, which consists of the anchor magnet and magnetic grasping apparatus. Surgical time, intraoperative blood loss, intraoperative accidents, operator experience, postoperative incision pain score, postoperative complications, and other indicators were evaluated and analyzed.

RESULTS

All eight patients underwent a MAT-assisted laparoscopic left lateral segment liver resection, including three patients undertaking conventional 5-port and five patients having a transumbilical single-port operation. The mean operation time was 138 ± 34.32 min (range 95-185 min) and the mean intraoperative blood loss was 123 ± 88.60 mL (range 20-300 mL). No adverse events occurred during the operation. The Y-Z MADs showed good workability and maneuverability in both tissue and organ exposure. In particular, the operators did not experience either a "chopstick" or "sword-fight" effect in the single-port laparoscopic operation.

CONCLUSION

The results show that the MAT is safe and feasible for laparoscopic left lateral segment liver resection, especially, exhibits its unique abettance for transumbilical single-port laparoscopic left lateral segment liver resection.

Impact of open hepatectomy on postoperative bile leakage in patients with biliary tract cancer

BACKGROUND

Bile leakage is a common and serious complication of open hepatectomy for the treatment of biliary tract cancer.

AIM

To evaluate the incidence, risk factors, and management of bile leakage after open hepatectomy in patients with biliary tract cancer.

METHODS

We retrospectively analyzed 120 patients who underwent open hepatectomy for biliary tract cancer from February 2018 to February 2023. Bile leak was defined as bile drainage from the surgical site or drain or the presence of a biloma on imaging. The incidence, severity, timing, location, and treatment of the bile leaks were recorded. The risk factors for bile leakage were analyzed using univariate and multivariate logistic regression analyses.

RESULTS

The incidence of bile leak was 16.7% (20/120), and most cases were grade A (75%, 15/20) according to the International Study Group of Liver Surgery classification. The median time of onset was 5 d (range, 1-14 d), and the median duration was 7 d (range, 2-28 d). The most common location of bile leakage was the cut surface of the liver (70%, 14/20), followed by the anastomosis site (25%, 5/20) and the cystic duct stump (5%, 1/20). Most bile leaks were treated conservatively with drainage, antibiotics, and nutritional support (85%, 17/20), whereas some required endoscopic retrograde cholangiopancreatography with stenting (10%, 2/20) or percutaneous transhepatic cholangiography with drainage (5%, 1/20). Risk factors for bile leakage include male sex, hepatocellular carcinoma, major hepatectomy, blood loss, and blood transfusion.

CONCLUSION

Bile leakage is a frequent complication of open hepatectomy for biliary tract cancer. However, most cases are mild and can be conservatively managed. Male sex, hepatocellular carcinoma, major hepatectomy, blood loss, and blood transfusion were associated with an increased risk of bile leak.

Minimally Invasive Hepatopancreatobiliary Surgery at a Large Regional Health System: Assessing the Safety of Program Expansion

BACKGROUND

Complex, minimally invasive hepatopancreatobiliary surgery (MIS HPB) is safe at high-volume centers, yet outcomes during early implementation are unknown. We describe our experience during period of rapid growth in an MIS HPB program at a large regional health system.

METHODS

During an increase in MIS HPB (60% greater from preceding year), hospital records of patients who underwent HPB surgery between 1/1/2019 and 12/31/2020 were reviewed. Operative time, estimated blood loss (EBL), conversion rates, length of stay (LOS), and perioperative outcomes were assessed.

RESULTS

267 patients' cases were reviewed. The population was 62 ± 13 years, 50% female, 90% white. MIS was more frequently performed for hepatic than pancreatic resections (59% vs 21%, P < .001). Open cases were more frequently performed for invasive malignancy in both pancreatic (70% vs 40%, P < .018) and hepatic (87% vs 70%, P = .046) resections. There was no difference in operative time between MIS and open surgery (293[218-355]min vs 296[199-399]min, P = .893). When compared to open, there was a shorter LOS (4[2-6]d vs 7[6-10]d, P < .001) and lower readmission rate (21% vs 37%, P = .005) following MIS. Estimated blood loss was lower in MIS liver resections, particularly when performed for benign disease (200[63-500]mL vs 600[200-1200]mL, P = .041). Overall 30-day mortality was similar between MIS and open surgery (1.0% vs 1.8%, P = 1.000).

DISCUSSION

During a surgical expansion phase within our regional health system, MIS HPB offered improved perioperative outcomes when compared to open surgery. These data support the safety of implementation even during intervals of rapid programmatic growth.

Comparing Outcomes of Minimally Invasive and Open Hepatectomy for Primary Liver Malignancies in Patients with Low-MELD Cirrhosis

INTRODUCTION

Cirrhotic patients with primary liver cancer may undergo curative-intent resection when selected appropriately. Patients with T1 tumors and low-MELD are generally referred for resection. We aim to evaluate whether minimally invasive hepatectomy (MIH) is associated with improved outcomes versus open hepatectomy (OH).

METHODS

NSQIP hepatectomy database 2014-2021 was used to select patients with T1 Hepatocellular Carcinoma (HCC) or Intra-hepatic Cholangiocarcionoma (IHCC) and low-MELD cirrhosis (MELD ≤ 10) who underwent partial hepatectomy. Propensity score matching was applied between OH and MIH patients, and 30-day postoperative outcomes were compared. Multivariable regression was used to identify predictors of post-hepatectomy liver failure (PHLF) in the selected population.

RESULTS

There were 922 patients: 494 (53.6%) OH, 372 (40.3%) MIH, and 56 (6.1%) began MIH converted to OH (analyzed with the OH cohort). We matched 354 pairs of patients with an adequate balance between the groups. MIH was associated with lower rates of bile leak (HR 0.37 [0.19-0.72)], PHLF (HR 0.36 [0.15-0.86]), collections requiring drainage (HR 0.30 [0.15-0.63]), postoperative transfusion (HR 0.36 [0.21-0.61]), major (HR 0.45 [0.27-0.77]), and overall morbidity (HR 0.44 [0.31-0.63]), and a two-day shorter median hospitalization (3 vs. 5 days; HR 0.61 [0.45-0.82]). No difference was noted in operative time, wound, respiratory, and septic complications, or mortality. Regression analysis identified ascites, prior portal vein embolization (PVE), additional hepatectomies, Pringle's maneuver, and OH (vs. MIH) as independent predictors of PHLF.

CONCLUSION

MIH for early-stage HCC/IHCC in low-MELD cirrhotic patients was associated with improved postoperative outcomes over OH. These findings suggest that MIH should be considered an acceptable approach in this population of patients.

Laparoscopic right posterior sectionectomy for a large hepatocellular carcinoma close to inferior vena cava

Approximately 20% of hepatocellular carcinomas (HCC) occur in noncirrhotic livers. Resection may be considered for patients with HCC, provided sufficient future liver remnant is available, regardless of the tumor size. Tumors located posteriorly near the right hepatic vein (RHV), or inferior vena cava can be managed through anterior or caudal approaches. RHV is typically conserved during right posterior sectionectomy. When a large posteriorly placed tumor causes chronic compression on RHV, the right anterior section drainage is redirected preferentially to the middle hepatic vein. The division of RHV in such instances does not cause congestion of segments 8 and 5. The technical complexity of laparoscopic right posterior sectionectomy arises from the large transection surface, positioned horizontally. We describe in this multimedia article, a case of large HCC in segments 6 and 7, which was successfully treated using laparoscopic anatomic right posterior sectionectomy.

Impact of liver cirrhosis, the severity of cirrhosis, and portal hypertension on the outcomes of minimally invasive left lateral sectionectomies for primary liver malignancies

BACKGROUND

The impact of cirrhosis and portal hypertension on perioperative outcomes of minimally invasive left lateral sectionectomies remains unclear. We aimed to compare the perioperative outcomes between patients with preserved and compromised liver function (noncirrhotics versus Child-Pugh A) when undergoing minimally invasive left lateral sectionectomies. In addition, we aimed to determine if the extent of cirrhosis (Child-Pugh A versus B) and the presence of portal hypertension had a significant impact on perioperative outcomes.

METHODS

This was an international multicenter retrospective analysis of 1,526 patients who underwent minimally invasive left lateral sectionectomies for primary liver malignancies at 60 centers worldwide between 2004 and 2021. In the study, 1,370 patients met the inclusion criteria and formed the final study group. Baseline clinicopathological characteristics and perioperative outcomes of these patients were compared. To minimize confounding factors, 1:1 propensity score matching and coarsened exact matching were performed.

RESULTS

The study group comprised 559, 753, and 58 patients who did not have cirrhosis, Child-Pugh A, and Child-Pugh B cirrhosis, respectively. Six-hundred and thirty patients with cirrhosis had portal hypertension, and 170 did not. After propensity score matching and coarsened exact matching, Child-Pugh A patients with cirrhosis undergoing minimally invasive left lateral sectionectomies had longer operative time, higher intraoperative blood loss, higher transfusion rate, and longer hospital stay than patients without cirrhosis. The extent of cirrhosis did not significantly impact perioperative outcomes except for a longer duration of hospital stay.

CONCLUSION

Liver cirrhosis adversely affected the intraoperative technical difficulty and perioperative outcomes of minimally invasive left lateral sectionectomies.

Risk factors and outcomes for cholangitis after hepatic resection

INTRODUCTION

There is a paucity in the literature in regard to the incidence, risk factors, and outcomes for post-operative cholangitis following hepatic resection.

METHODS

Retrospective review of the ACS NSQIP main and targeted hepatectomy registries for 2012-2016.

RESULTS

A total of 11,243 cases met the selection criteria. The incidence of post-operative cholangitis was 0.64% (151 cases). Multivariate analysis identified several risk factors associated with the development of post-operative cholangitis, stratified out by pre-operative and operative factors. The most significant risk factors were biliary anastomosis and pre-operative biliary stenting with odds ratios (OR) of 32.39 (95% CI 22.91-45.79, P value < 0.0001) and 18.32 (95% CI 10.51-31.94, P value < 0.0001) respectively. Cholangitis was significantly associated with post-operative bile leaks, liver failure, renal failure, organ space infections, sepsis/septic shock, need for reoperation, longer length of stay, increased readmission rates, and death.

CONCLUSION

Largest analysis of post-operative cholangitis following hepatic resection. While a rare occurrence, it is associated with significantly increased risk for severe morbidity and mortality. The most significant risk factors were biliary anastomosis and stenting.

Safety and effectiveness of fluorescence laparoscopy in precise hepatectomy: A meta-analysis

BACKGROUND

To perform a systematic review of the safety and effectiveness of fluorescence laparoscopy-guided precise hepatectomy.

METHODS

We searched the PubMed, Embase, Web of Science, and Cochrane Library databases from inception to December 1, 2022, using the search terms "indocyanine green," "ICG," "infracyanine green," "laparoscopy," "liver resection," and "hepatectomy." After performing a methodological quality assessment of the included studies, the overall results were subjected to meta-analysis using Review Manager 5.3.

RESULTS

After screening, the meta-analysis included a total of 13 articles. The studies included 1,115 patients who were grouped into the fluorescence laparoscopy (490 patients) and conventional laparoscopy (625 patients) groups. All articles included in the meta-analysis were of high quality. The results of the meta-analysis revealed that compared to the conventional laparoscopy group, the fluorescence laparoscopy group had a higher R0 resection rate (odds ratio=4.03, 95% confidence interval [1.50, 10.83], P=0.006), lower blood transfusion rate (odds ratio=0.46, 95% confidence interval [0.21, 0.97], P=0.04) and lower blood loss (mean difference=-36.58; 95% confidence interval [-59.75, -13.41], P=0.002). However, the length of hospital stay, operative time, and incidence of postoperative complications did not differ significantly between both groups (P>0.05).

CONCLUSION

Compared to conventional laparoscopy, fluorescence laparoscopy provides better application effects in hepatectomy. The surgical procedure has demonstrated good safety and feasibility, which make it worthy of popularization.

Right Kidney Position for Laparoscopic Liver Resection of Tumors Located in the Posterosuperior Region

BACKGROUND

Laparoscopic liver resection (LLR) for tumors located in posterosuperior (PS) region of the liver (segment 7 or 8) is extremely challenging. Several techniques have been proposed; however, no standard procedure has yet been established. The aim of this study was to present and discuss the usefulness of the right kidney position as a unique idea of surgical position in LLR for tumors located in the PS region.

MATERIALS AND METHODS

For the right kidney position, the patient lay on the operating table in the left lateral decubitus position with the body bent so that the kidney rest (approximately the level of the twelfth rib) was elevated to extend the surgical area. The surgeon was positioned on the right or left side of the patient according to the situation during operation. An intercostal port was not used in any of the cases. The operating table was liberally rotated as per the surgeon's preference. The liver was mobilized by dividing the right triangular and coronary ligaments. Full mobilization of the right liver was not routinely performed. Liver transection was performed under intermittent inflow occlusion in all cases.

RESULTS

Thirteen patients with tumors located in the PS region underwent LLR in the right kidney position at Shinshu University Hospital between June 2019 and May 2021. Of the 13 patients, 11 patients underwent limited liver resection and two underwent anatomic liver resection of segment 8. The right kidney position enables the surgeon to secure a wider surgical field under the dome and prevent the camera and forceps from hitting the ilium and interfering with the operation, and the surgical device can easily reach the lesion under the dome because of the migration to the caudal side of the liver. No patients required blood transfusion or conversion to open liver resection. The median surgical margin was 6 mm (range 0 to 9 mm).

CONCLUSIONS

The right kidney position is useful, especially for the resection of tumors located in the PS region of the liver.

Laparoscopic and Robot-Assisted Hepatic Surgery: An Historical Review

Hepatic surgery is a rapidly expanding component of abdominal surgery and is performed for a wide range of indications. The introduction of laparoscopic cholecystectomy in 1987 was a major change in abdominal surgery. Laparoscopic surgery was widely and rapidly adopted throughout the world for cholecystectomy initially and then applied to a variety of other procedures. Laparoscopic surgery became regularly applied to hepatic surgery, including segmental and major resections as well as organ donation. Many operations progressed from open surgery to laparoscopy to robot-assisted surgery, including colon resection, pancreatectomy, splenectomy thyroidectomy, adrenalectomy, prostatectomy, gastrectomy, and others. It is difficult to prove a data-based benefit using robot-assisted surgery, although laparoscopic and robot-assisted surgery of the liver are not inferior regarding major outcomes. When laparoscopic surgery initially became popular, many had concerns about its use to treat malignancies. Robot-assisted surgery is being used to treat a variety of benign and malignant conditions, and studies have shown no deterioration in outcomes. Robot-assisted surgery for the treatment of malignancies has become accepted and is now being used at more centers. The outcomes after robot-assisted surgery depend on its use at specialized centers, the surgeon's personal experience backed up by extensive training and maintenance of international registries. Robot-assisted hepatic surgery has been shown to be associated with slightly less intraoperative blood loss and shorter hospital lengths of stay compared to open surgery. Oncologic outcomes have been maintained, and some studies show higher rates of R0 resections. Patients who need surgery for liver lesions should identify a surgeon they trust and should not be concerned with the specific operative approach used. The growth of robot-assisted surgery of the liver has occurred in a stepwise approach which is very different from the frenzy that was seen with the introduction of laparoscopic cholecystectomy. This approach allowed the identification of areas for improvement, many of which are at the nexus of engineering and medicine. Further improvements in robot-assisted surgery depend on the combined efforts of engineers and surgeons.

Robot-assisted liver resection: the real benefit so far

BACKGROUND

Minimally invasive liver resection is associated with lower perioperative morbidity and shorter hospital stay. However, the added benefit of the robotic platform over conventional laparoscopy is a matter of ongoing investigation.

PURPOSE

The purpose of this narrative review is to provide an up-to-date and balanced evaluation of the benefits and shortcomings of robotic liver surgery for the modern hepatobiliary surgeon.

CONCLUSIONS

Advantages of a robotic approach to liver resection include a shortened learning curve, the ability to complete more extensive or complex minimally invasive operations, and integrated fluorescence guidance. However, the robotic platform remains limited by a paucity of parenchymal transection devices, complete lack of haptic feedback, and added operating time associated with docking and instrument exchange. Like laparoscopic hepatectomy, robotic hepatectomy may provide patients with more rapid recovery and a shorter hospital stay, which can help offset the substantial costs of robot acquisition and maintenance. The oncologic outcomes of robotic hepatectomy appear to be equivalent to laparoscopic and open hepatectomy for appropriately selected patients.

Study: International Multicentric Minimally Invasive Liver Resection for Colorectal Liver Metastases (SIMMILR-CRLM)

(1) Background: Here we report on a retrospective study of an international multicentric cohort after minimally invasive liver resection (SIMMILR) of colorectal liver metastases (CRLM) from six centers. (2) Methods: Resections were divided by the approach used: open liver resection (OLR), laparoscopic liver resection (LLR) and robotic liver resection (RLR). Patients with macrovascular invasion, more than three metastases measuring more than 3 cm or a solitary metastasis more than 5 cm were excluded, and any remaining heterogeneity found was further analyzed after propensity score matching (PSM) to decrease any potential bias. (3) Results: Prior to matching, 566 patients underwent OLR, 462 LLR and 36 RLR for CRLM. After PSM, 142 patients were in each group of the OLR vs. LLR group and 22 in the OLR vs. RLR and 21 in the LLR vs. RLR groups. Blood loss, hospital stay, and morbidity rates were all highly statistically significantly increased in the OLR compared to the LLR group, 636 mL vs. 353 mL, 9 vs. 5 days and 25% vs. 6%, respectively (p < 0.001). Only blood loss was significantly decreased when RLR was compared to OLR and LLR, 250 mL vs. 597 mL, and 224 mL vs. 778 mL, p < 0.008 and p < 0.04, respectively. (4) Conclusions: SIMMILR indicates that minimally invasive approaches for CRLM that follow the Milan criteria may have short term advantages. Notably, larger studies with long-term follow-up comparing robotic resections to both OLR and LLR are still needed.

A Hybrid Machine Learning Model Based on Semantic Information Can Optimize Treatment Decision for Naïve Single 3-5-cm HCC Patients

BACKGROUND

Tumor recurrence is an abomination for hepatocellular carcinoma (HCC) patients receiving local treatment.

PURPOSE

The aim of the study was to build a hybrid machine learning model to recommend optimized first treatment (laparoscopic hepatectomy [LH] or microwave ablation [MWA]) for naïve single 3-5-cm HCC patients based on early recurrence (ER, ≤2 years) probability.

METHODS

This retrospective study collected 20 semantic variables of 582 patients (LH: 300, MWA: 282) from 13 hospitals with at least 24 months follow-up. Both groups were divided into training, validation, and test set, respectively. Five algorithms (logistics regression, random forest, neural network, stochastic gradient boosting, and eXtreme Gradient Boosting [XGB]) were used for model building. A model with highest area under the receiver operating characteristic curve (AUC) in a validation set of LH and MWA was selected to connect as a hybrid model which made decision based on ER probability. Model testing was performed in a comprehensive set comprising LH and MWA test sets.

RESULTS

Four variables in each group were selected to build LH and MWA models, respectively. LH-XGB model (AUC = 0.744) and MWA-stochastic gradient method (AUC = 0.750) model were selected for model building. In the comprehensive set, a treatment confusion matrix was established based on recommended and actual treatment. The predicted ER probabilities were comparable with the actual ER rates for various types of patients in matrix (p > 0.05). ER rate of patients whose actual treatment consistent with recommendation was lower than that of inconsistent patients (LH: 21.2% vs. 46.2%, p = 0.042; MWA: 26.3% vs. 54.1%, p = 0.048). By recommending optimal treatment, the hybrid model can significantly reduce ER probability from 38.2% to 25.6% for overall patients (p < 0.001).

CONCLUSIONS

The hybrid model can accurately predict ER probability of different treatments and thereby provide reliable evidence to make optimal treatment decision for patients with single 3-5-cm HCC.

Pure laparoscopic living donor liver transplantation: Dreams come true

Minimally invasive approaches are increasingly being applied in surgeries and have recently been used in living donor hepatectomy. We have developed a safe and reproducible method for minimally invasive living donor liver transplantation, which consists of pure laparoscopic explant hepatectomy and pure laparoscopic implantation of the graft, which was inserted through a suprapubic incision. Pure laparoscopic explant hepatectomy without liver fragmentation was performed in a 60-year-old man with alcoholic liver cirrhosis and hepatocellular carcinoma. The explanted liver was retrieved through a suprapubic incision. A modified right liver graft, procured from his 24-year-old son using the pure laparoscopic method, was inserted through a suprapubic incision, and implantation was performed intracorporeally throughout the procedure. The time required to remove the liver was 369 min, and the total operative time was 960 min. No complications occurred during or after the surgery. The patient recovered well, and his hospital stay was of 11 days. Pure laparoscopic living donor liver transplantation from explant hepatectomy to implantation was performed successfully. It is a feasible procedure when performed by a highly experienced surgeon and transplantation team. Further studies with larger sample sizes are needed to confirm its safety and feasibility.

Limited upper midline incision for major hepatectomy in adults: safety and feasibility

Objective: Optimal incision for major hepatectomy remains controversial. In this study, we described our experience with a limited upper midline incision (UMI) for major hepatectomy. The objective was to analyze the feasibility and safety of UMI in major hepatectomy.

Material and Methods: Fifty-seven consecutive patients who underwent major hepatectomies performed via an UMI were compared to a control group of 36 patients who underwent major hepatectomies with a conventional incision (CI).

Results: In 85% of the patients, the indication was malignancy, with a median tumor size of 6 cm. Fifty-three percent of the patients had underlying chronic liver disease, and liver fibrosis was found in 61% of the patients. Ninteen percent of the patients had previous upper abdominal surgery. Twenty- six patients underwent left hepatectomy, 20 patients had right hepatectomy and 11 patients trisegmentectomy. Additional combined surgical proce- dures were performed in 42% of the patients. Median operative time was 323 minutes, estimated blood loss was 500 ml, and median post-operative hospital stay was seven days. Surgical complications occurred in 22 patients (39%). 5-year overall survival was 67%. When compared with the control group with CI, patients with UMI had no statistical difference on operative time, estimated blood loss, length of hospital stay, complication rate, and overall survival.

Conclusion: Major hepatectomies can be safely performed through UMI. This approach should be considered as a reasonable option in addition to conventional and laparoscopic approaches for major hepatectomies.

A Single Institution's Experience With Robotic Minor and Major Hepatectomy

BACKGROUND

Minimally invasive liver resection is gradually becoming the preferred technique to treat liver tumors due its salutary benefits when compared with traditional "open" method. While robotic technology improves surgeon dexterity to better perform complex operations, outcomes of robotic hepatectomy have not been adequately studied. We therefore describe our institutional experience with robotic minor and major hepatectomy.

MATERIALS AND METHODS

We prospectively study all patients undergoing robotic hepatectomy from 2016 to 2020.

RESULTS

A total of 220 patients underwent robotic hepatectomy. 138 (63%) were major hepatectomies while 82 (37%) were minor hepatectomies. Median age was 63 (62 ± 13) years, 118 (54%) were female. 168 patients had neoplastic disease and 52 patients had benign disease. Lesion size in patients who had undergone minor hepatectomy was 2 (3 ± 2.5) cm, compared to 5 (5 ± 3.0) cm in patients who undergone major hepatectomy (P < .001). 97% of patients underwent R0 resections while none of the patients had R2 resection. Operative duration was 226 (260 ± 122.7) vs 282 (299 ± 118.7) minutes (P ≤ .05); estimated blood loss was 100 (163 ± 259.2) vs 200 (251 ± 246.7) mL (P ≤ .05) for minor and major hepatectomy, respectively. One patient had intraoperative bleeding requiring "open" conversion. Nine (4%) patients had experienced notable postoperative complications and 2 (1%) patients died postoperatively. Length of stay was 3 (5 ± 4.6) vs 4 (5 ± 2.8) days for minor vs major hepatectomy (P = .84). Reoperation and readmission rate for minor vs major hepatectomy was 1% vs 3% (P = .65) and 9% vs 10% (P = .81), respectively.

DISCUSSION

Robotic major hepatectomy is safe, feasible, and efficacious with excellent postoperative outcomes.

Minimally invasive liver resection for huge (≥10 cm) tumors: an international multicenter matched cohort study with regression discontinuity analyses

Background

The application and feasibility of minimally invasive liver resection (MILR) for huge liver tumours (≥10 cm) has not been well documented.

Methods

Retrospective analysis of data on 6,617 patients who had MILR for liver tumours were gathered from 21 international centers between 2009-2019. Huge tumors and large tumors were defined as tumors with a size ≥10.0 cm and 3.0-9.9 cm based on histology, respectively. 1:1 coarsened exact-matching (CEM) and 1:2 Mahalanobis distance-matching (MDM) was performed according to clinically-selected variables. Regression discontinuity analyses were performed as an additional line of sensitivity analysis to estimate local treatment effects at the 10-cm tumor size cutoff.

Results

Of 2,890 patients with tumours ≥3 cm, there were 205 huge tumors. After 1:1 CEM, 174 huge tumors were matched to 174 large tumors; and after 1:2 MDM, 190 huge tumours were matched to 380 large tumours. There was significantly and consistently increased intraoperative blood loss, frequency in the application of Pringle maneuver, major morbidity and postoperative stay in the huge tumour group compared to the large tumour group after both 1:1 CEM and 1:2 MDM. These findings were reinforced in RD analyses. Intraoperative blood transfusion rate and open conversion rate were significantly higher in the huge tumor group after only 1:2 MDM but not 1:1 CEM.

Conclusions

MILR for huge tumours can be safely performed in expert centers It is an operation with substantial complexity and high technical requirement, with worse perioperative outcomes compared to MILR for large tumors, therefore judicious patient selection is pivotal.

Efficacy of radiofrequency ablation versus laparoscopic liver resection for hepatocellular carcinoma in China: a comprehensive meta-analysis

INTRODUCTION

Hepatocellular carcinoma (HCC) has been the second leading cause of cancer-related death in China. Radiofrequency ablation is a relatively novel treatment that may improve the treatment of HCC.

AIM

To evaluate and compare the efficacy and safety of radiofrequency ablation (RFA) versus laparoscopic liver resection (LLR) in the treatment of HCC.

MATERIAL AND METHODS

We searched for relevant published studies in English (PubMed, Cochrane Library, EMBASE) and in Chinese (CBM, CNKI and Wanfang) from their inception until September 23, 2019. The quality of included studies was evaluated by the Newcastle-Ottawa Scale.

RESULTS

A total of 19 retrospective studies including 2038 patients were eligible for the meta-analysis. The results of the meta-analysis demonstrated that LLR was superior to RFA in terms of 3-year overall survival rate (OR = 0.62), 1 to 3-year disease-free survival rates (OR = 0.57; OR = 0.41, respectively) and local recurrence rates (OR = 2.71).

CONCLUSIONS

The meta-analysis demonstrates that laparoscopic liver resection should be preferred in tumors of size 3-5 cm, while for < 3 cm the long term results are equal.

Initial experience with a robotic hepatectomy program at a high-volume laparoscopic center: single-center experience and surgical tips

Background

Despite the development of laparoscopic surgery, there are still inherent limitations associated with conventional laparoscopic instruments such as restrictions in movement and an inability for articulation. Robotic surgery may help to overcome the limitations of conventional laparoscopic surgery. The aim of this study was to present our initial experience with robotic hepatectomy (RH) and discuss the steps required to develop an RH program at a high-volume laparoscopic hepatectomy (LH) center.

Methods

We retrospectively reviewed prospectively collected data for 14 consecutive patients who underwent RH between 2017 and 2018. Clinicopathological characteristics and perioperative outcomes were compared with those reported in previous studies. The operation time of each procedure was analyzed to assess RH proficiency based on experience.

Results

Of the 14 patients, 12 patients (85.7%) underwent robotic major hepatectomy. Median patient age was 54.5 years, while median body mass index (BMI) was 25.2 kg/m². The median operation time was 360 (range: 145–544) min. The median estimated blood loss (EBL) was 300 (range: 50–1,400) mL. Conversion to open surgery was not required in any case. The median length of hospital stay was 5 (range: 4–14) days. Major complications occurred in 2 patients (14.2%), although both recovered without sequelae. The time required for hilar dissection, docking, and parenchymal transection gradually decreased after the first two cases of RH.

Conclusions

From our initial experience, RH might be considered as a feasible procedure in the liver resection, even in major hepatectomy. In addition, surgeons with sufficient experience in LH could rapidly adapt for RH. However, we have to make a system for education and monitoring of this innovative surgery for the patients’ safety.

Multicenter Propensity Score-Based Study of Laparoscopic Repeat Liver Resection for Hepatocellular Carcinoma: A Subgroup Analysis of Cases with Tumors Far from Major Vessels

Simple Summary

Less morbidity is considered among the advantages of laparoscopic liver resection for HCC patients. However, our previous international, multi-institutional study of laparoscopic repeat liver resection (LRLR) failed to prove it. We hypothesize that these results may be since the study included complex cases performed during the procedure’s developing stage. To examine it, subgroup analysis based on propensity score were performed, defining the proximity of the tumors to major vessels as the complexity. A propensity score matching earned 115 each patient of LRLR and open repeat liver resection (ORLR) without the proximity to major vessels, and the outcomes were compared. With comparable operation time and long-term outcome, less blood loss and less morbidity were shown in LRLR group than ORLR. Even in its worldwide developing stage, LRLR for HCC patients could be beneficial in blood loss and morbidity for the patients with less complexity in surgery.

Abstract

Less morbidity is considered among the advantages of laparoscopic liver resection (LLR) for HCC patients. However, our previous international, multi-institutional, propensity score-based study of emerging laparoscopic repeat liver resection (LRLR) failed to prove this advantage. We hypothesize that these results may be since the study included complex LRLR cases performed during the procedure’s developing stage. To examine it, subgroup analysis based on propensity score were performed, defining the proximity of the tumors to major vessels as the indicator of complex cases. Among 1582 LRLR cases from 42 international high-volume liver surgery centers, 620 cases without the proximity to major vessels (more than 1 cm far from both first–second branches of Glissonian pedicles and major hepatic veins) were selected for this subgroup analysis. A propensity score matching (PSM) analysis was performed based on their patient characteristics, preoperative liver function, tumor characteristics and surgical procedures. One hundred and fifteen of each patient groups of LRLR and open repeat liver resection (ORLR) were earned, and the outcomes were compared. Backgrounds were well-balanced between LRLR and ORLR groups after matching. With comparable operation time and long-term outcome, less blood loss (283.3±823.0 vs. 603.5±664.9 mL, p = 0.001) and less morbidity (8.7 vs. 18.3 %, p = 0.034) were shown in LRLR group than ORLR. Even in its worldwide developing stage, LRLR for HCC patients could be beneficial in blood loss and morbidity for the patients with less complexity in surgery.

Usefulness and safety of midline incision for right-sided hepatectomy: Cohort study

Background

While the adoption rates of laparoscopic hepatectomy are increasing, most patients still undergo open hepatectomy. Open hepatectomies use inverted L-shaped or Mercedes incisions for right-sided liver tumor. To decrease procedural invasiveness, we performed midline incisions in such cases, excluding those of laparoscopic hepatectomy. This retrospective study examined the effects of this change in treatment policy on overall patient surgical outcomes.

Materials and methods

From 2012 to 2018, 374 patients who underwent hepatectomy for right-sided hepatocellular carcinoma were enrolled, and short-term patient outcomes were compared following stratification into the 1st (n = 157) or 2nd (n = 217) Era group based on whether procedures occurred before or after the policy change, respectively.

Results

Short-term outcomes were mostly comparable between the two groups, with significantly increased postoperative aspartate aminotransferase maximum values found in the 2nd Era group relative to the 1st Era group (median: 393 vs. 331, p < 0.05). Pain scores at rest during postoperative day 1 and while moving on postoperative days 1, 2, and 3 were significantly lower in the 2nd Era group than in the 1st Era group (p < 0.05, <0.01, <0.05, <0.01, respectively).

Conclusions

Utilization of midline incisions may provide some benefits in postoperative outcomes for right-sided open hepatectomy cases.

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Utilization of midline incisions may provide better postoperative outcomes in cases of right-sided open hepatectomy.

Safety and efficacy of laparoscopic repeat liver resection and re-operation for liver tumor

Laparoscopic liver resection (LLR) has been reported as a safe, minimally invasive, and effective surgery for the management of liver tumor. However, the efficacy and safety of laparoscopic repeat liver resection (LRLR) for recurrent liver tumor are unclear. Here, we analyzed the surgical results of LRLR. From June 2010 to May 2019, we performed 575 LLR surgeries in our department, and 454 of them underwent pure LLR for the single tumor. We classified the patients who received pure LLR for the single tumor into three groups: LRLR (n = 80), laparoscopic re-operation after previous abdominal surgery (LReOp; n = 136), and laparoscopic primary liver resection (LPLR; n = 238). We compared patient characteristics and surgical results between patients undergoing LRLR, LReOp and LPLR. We found no significant differences between LRLR and LPLR in the conversion rate to laparotomy (p = 0.8033), intraoperative bleeding (63.0 vs. 152.4 ml; p = 0.0911), or postoperative bile leakage rate (2.50 vs. 3.78%; p = 0.7367). We also found no significant difference in the surgical results between LReOp and LPLR. However, the number of patients undergoing the Pringle maneuver was lower in the LRLR group than the LPLR group (61.3 vs. 81.5%; p = 0.0004). This finding was more pronounced after open liver resection than laparoscopic liver resection (38.9 vs. 67.7%; p = 0.0270). The operative time was significantly longer in patients with proximity to previous cut surface than patients with no proximity to previous cut surface (307.4 vs. 235.7 min; p = 0.0201). LRLR can safely be performed with useful surgical results compared to LPLR.

Meta-analysis of indocyanine green fluorescence imaging-guided laparoscopic hepatectomy

BACKGROUND

This meta-analysis was conducted to systematically evaluate the short-term efficacy and safety of indocyanine green (ICG) fluorescence imaging-guided laparoscopic hepatectomy.

METHODS

A systematic search was conducted of the literature on ICG fluorescence imaging-guided laparoscopic hepatectomy in randomized, semi-randomized controlled trials and observational studies. The found publications and conference papers in English were manually searched and the references included in the literature were traced. The retrieval period was up to February 2021. After evaluating the quality of the included studies, the meta-analysis was conducted using the STATA 15.1 software.

RESULTS

This meta-analysis included 6 studies comprising 417 patients with liver disease. The meta-results showed that compared to the control group, ICG fluorescence imaging-guided laparoscopic hepatectomy can significantly shorten the operative time [weighted mean differences (WMD) = -20.81, 95% CI, -28.02--13.59, p = 0.000], reduce intraoperative bleeding  [WMD = -108.16, 95% CI, -127.88--88.44, p = 0.000], shorten hospital stay  [WMD= -1.23,95% CI, -1.50--0.95, p = 0.000], and reduce the incidence of postoperative complications  [OR = 0.49,95% CI, 0.26-0.91, p = 0.025]. There were no differences in blood transfusion, hilar occlusion time, and surgical margin.

CONCLUSION

The application of ICG fluorescence imaging technology in laparoscopic hepatectomy can effectively reduce the operative time, blood loss, hospital stay and the incidence of postoperative complications. However, more multicenter large-sample randomized controlled trials are needed to further confirm its advantages.

Hand-assisted Laparoscopic Repeat Hepatectomy for Secondary Liver Neoplasm

BACKGROUND

Hand-assisted laparoscopic surgery is a widely accepted alternative to an open approach. The use of this technique in repeat liver resection is limited due to technical difficulties caused by postsurgical adhesions. We aimed to assess the feasibility and safety of hand-assisted laparoscopic repeat hepatectomy (HALRH).

MATERIALS AND METHODS

This was a retrospective study of the medical files of patients who had undergone HALRH between 2010 and 2017 in 2 university-affiliated medical centers.

RESULTS

Sixteen patients with repeat hepatectomy were included with a median age of 67.5 years. The first liver resection was a traditional laparotomy for 9 patients and hand-assisted laparoscopic surgery for 7 patients. The conversion rate to open surgery was 6%. The median operative time, blood loss during surgery, and postoperative hospital stay were 166 minutes, 400 mL, and 7 days, respectively. R0 resections were achieved in 88% of patients. The median number of tumors and tumor size were 1 and of 25 mm, respectively. There were no mortalities or major complications postoperatively. For patients with colorectal liver metastases, the median follow-up and overall survival were 21 and 43 months, respectively.

CONCLUSION

The findings suggest HALRH to be safe and feasible. Future ERAS guidelines should evaluate this approach for liver surgery.

Hand-assisted Laparoscopic Surgery for Colorectal Liver Metastasis: Analysis of Short-term and Long-term Results

BACKGROUND

There is scant data regarding the outcomes of hand-assisted laparoscopic surgery (HALS) for colorectal liver metastasis (CRLM). The aim of this study is to report our experience and analyze the short-term and long-term results.

MATERIALS AND METHODS

Retrospective study of patients undergoing HALS for CRLM in 2 university affiliated medical centers.

RESULTS

Two hundred and thirty-eight liver procedures were performed on 145 patients including 205 parenchymal sparing resections and 33 anatomic resections. The median number of metastases was 1 (range: 1 to 8), 38 patients (26.2%) had 3 or more metastases, and 41 patients (28.3 had a bi-lobar disease. The tumor size was 20 (2 to 90) mm, and 52 patients (36.6%) had a tumor larger than 30 mm. Nighty-nine patients (67.8%) received neoadjuvant chemotherapy. In 8 patients (5.5%) the laparoscopic liver resection was combined with ablation, and 16 patients (11%) underwent a synchronous resection of colorectal cancer. The median operative time, blood loss during surgery, and postoperative hospital stay were 163 minutes, 300 mL, and 4 days, respectively. The median modified Iwate complexity score was 4 (0 to 10) and the conversion rate to open surgery was 5.5%. The overall and major complication rates were 23.8% and 3.6%, respectively. The mortality rate was 0.7%. R0 resections were achieved in 91% of patients. Median overall survival for all the cohort (intend to treat) was 59 months, and the 8- and 10-year overall survival rates were 47.3% and 24.9%, respectively.

CONCLUSIONS

This study shows that HALS is a safe and efficacious treatment for selected patients with CRLM.

Postoperative outcomes of purely laparoscopic donor hepatectomy compared to open living donor hepatectomy: a preliminary observational study

Purpose

To lessen the physical, cosmetic, and psychological burden of donors, purely laparoscopic donor hepatectomy (PLDH) has been proposed as an ideal method for living donors. Our study aimed to prospectively compare the effect of PLDH and 2 other types of open living donor hepatectomy (OLDH) on postoperative pain and recovery.

Methods

Sixty donors scheduled to undergo donor hepatectomy between March 2015 and November 2017 were included. Donors were divided into 3 groups by surgical technique: OLDH with a subcostal incision (n = 20), group S; OLDH with an upper midline incision (n = 20), group M; and PLDH (n = 20), group L. The primary outcomes were postoperative pain and analgesic requirement during postoperative day (POD) 3. Other variables regarding postoperative recovery were also analyzed.

Results

Although pain relief during POD 3, assessed by visual analog scale (VAS) score and analgesic requirement, was similar among the 3 groups, group L showed lower VAS scores and opioid requirements than group M. Moreover, group L was associated with a rapid postoperative recovery evidenced by the shorter hospital length of stay and more frequent return to normal activity on POD 30.

Conclusion

This pilot study failed to verify the hypothesis that PLDH reduces postoperative pain. PLDH did not reduce postoperative pain but showed faster recovery than OLDH.

Robotic Versus Open Liver Resection in Hepatocarcinoma: Surgical and Oncological Outcomes

BACKGROUND

Minimally invasive approaches are spreading in every field of surgery, including liver surgery. However, studies comparing robotic hepatectomy with the conventional open approach regarding oncologic outcomes for hepatocellular carcinoma are limited.

MATERIALS AND METHODS

We retrospectively reviewed demographics characteristics, pathologic features, surgical, and oncological outcomes of patients who underwent robotic and conventional open liver resection for hepatocellular carcinoma.

RESULTS

No significant differences in demographics features, tumor size, tumor location, and type of liver resection were found. The morbidity rate was similar, 23% for the open group versus 17% of the robotic group (P=0.605). Perioperative data analysis showed a greater estimated blood loss in patients who underwent open resection, if compared with robotic group (P=0.003). R0 resection and disease-free resection margins showed no statistically significant differences. The 3-year disease-free survival of the robotic group was comparable with that of the open group (54% vs. 37%; P=0.592), as was the 3-year overall survival (87% vs. 78%; P=0.203).

CONCLUSIONS

The surgical and the oncological outcomes seem to be comparable between minimally invasive and open hepatectomy. Robotic liver resections are effective, and do not compromise the oncological outcome, representing a reasonable alternative to the open approach.

A self-designed liver circle for on-demand Pringle's manoeuver in laparoscopic liver resection

BACKGROUND

Laparoscopic liver resection (LLR) allows minimal incisions and relatively quicker post-operative recovery, while intraoperative massive haemorrhage led to conversion to laparotomy. This study aimed to introduce a new, safe and convenient device to serve as Pringle's manoeuver according to the demand in LLR.

METHODS

A liver circle consisting of a hole and a round stem with an obtuse small head was made by medical silica gel. It was applied in LLR to perform on-demand Pringle's manoeuver and developed its function in inferior vena cava (IVC) occlusion. The time of performing Pringle's manoeuver by liver circle, extracorporeal tourniquet and endo intestinal clip under laparoscopic simulator and LLR was compared.

RESULTS

The liver circle was successfully applied to perform Pringle's manoeuver, IVC exposure and occlusion. It took less time in the occluding step of Pringle's manoeuver than the extracorporeal tourniquet (4.15 ± 0.35 s vs. 9.90 ± 1.15 s, P < 0.05) and the endo intestinal clip (4.15 ± 0.35 s vs. 47.91 ± 3.98 s, P < 0.05) under LLR. The total manipulating time for Pringle's manoeuver with liver circle remained the shortest, and the advantages were more obvious with increased frequencies of intermittent Pringle's manoeuver.

CONCLUSION

The new-designed liver circle is more convenient compared to other techniques in performing Pringle's manoeuver, especially the intermittent Pringle's manoeuver in LLR. It can be used to perform on-demand hepatic blood inflow occlusion in every LLR by pre-circling the hepatoduodenal ligament to control bleeding during surgery. It can also be applied to expose the surgical field of vision and perform IVC occlusion to reduce intraoperative blood loss.

Comparison of Augmented Reality Display Techniques to Support Medical Needle Insertion

Augmented reality (AR) may be a useful technique to overcome issues of conventionally used navigation systems supporting medical needle insertions, like increased mental workload and complicated hand-eye coordination. Previous research primarily focused on the development of AR navigation systems designed for specific displaying devices, but differences between employed methods have not been investigated before. To this end, a user study involving a needle insertion task was conducted comparing different AR display techniques with a monitor-based approach as baseline condition for the visualization of navigation information. A video see-through stationary display, an optical see-through head-mounted display and a spatial AR projector-camera-system were investigated in this comparison. Results suggest advantages of using projected navigation information in terms of lower task completion time, lower angular deviation and affirmative subjective participant feedback. Techniques requiring the intermediate view on screens, i.e. the stationary display and the baseline condition, showed less favorable results. Thus, benefits of providing AR navigation information compared to a conventionally used method could be identified. Significant objective measures results, as well as an identification of advantages and disadvantages of individual display techniques contribute to the development and design of improved needle navigation systems.

The initiation, standardization and proficiency (ISP) phases of the learning curve for minimally invasive liver resection: comparison of a fellowship-trained surgeon with the pioneers and early adopters

BACKGROUND

Using the Ideal Development Exploration Assessment and Long-term study (IDEAL) paradigm, Halls et al. created risk-adjusted cumulative sum (RA-CUSUM) curves concluding that Pioneers (P) and Early Adopters (EA) of minimally invasive (MI) liver resection obtained similar results after fewer cases. In this study, we applied this framework to a MI Hepatic-Pancreatic and Biliary fellowship-trained surgeon (FT) in order to assess where along the curves this generation fell.

METHODS

The term FT was used to designate surgeons without previous independent operative experience who went from surgical residency directly into fellowship. Three phases of the learning curve were defined using published data on EAs and Ps of MI Hepatectomy, including phase 1 (initiation) (i.e., the first 17 or 50), phase 2 (standardization) (i.e., cases 18-46 or 1-50) and phase 3 (proficiency) (i.e., cases after 46, 50 or 135). Data analysis was performed using the Social Science Statistics software ( www.socscistatistics.com ). Statistical significance was defined as p < .05.

RESULTS

From November 2007 until April 2018, 95 MI hepatectomies were performed by a FT. During phase 1, the FT approached larger tumors than the EA group (p = 0.002), that were more often malignant (94.1%) when compared to the P group (52.5%) (p < 0.001). During phase 2, the FT operated on larger tumors and more malignancies (93.1%) when compared to the Ps (p = 0.004 and p = 0.017, respectively). However, there was no difference when compared to the EA. In the phase 3, the EAs tended to perform more major hepatectomies (58.7) when compared to either the FT (30.6%) (p = 0.002) or the P's cases 51-135 and after 135 (35.3% and 44.3%, respectively) (both p values < 0.001). When compared to the Ps cases from 51-135, the FT operated on more malignancies (p = 0.012), but this was no longer the case after 135 cases by the Ps (p = 0.164). There were no statistically significant differences when conversions; major complications or 30- and 90-day mortality were compared among these 3 groups.

DISCUSSION

Using the IDEAL framework and RA-CUSUM curves, a FT surgeon was found to have curves similar to EAs despite having no previous independent experience operating on the liver. As in our study, FTs may tend to approach larger and more malignant tumors and do more concomitant procedures in patients with higher ASA classifications than either of their predecessors, without statistically significant increases in major morbidity or mortality.

CONCLUSION

It is possible that the ISP (i.e., initiation, standardization, proficiency) model could apply to other innovative surgical procedures, creating different learning curves depending on where along the IDEAL paradigm surgeons fall.

Development of a Novel Wasp-Inspired Friction-Based Tissue Transportation Device

Currently existing tubular transportation systems for the extraction of large tissue masses during Minimal Invasive Surgery (MIS) are subjected to a large amount of operating limitations. In this study, a novel transportation mechanism (patented) was developed inspired by the egg-laying structure of wasps. The developed mechanism consists of an outer tube within which six reciprocating semi-cylindrical blades are present and tissue is transported using a friction differential between the blades. Two motion sequences were developed: (1) 1–5 motion sequence, in which one blade moves forward, while the remaining five blades move backward and (2) 2–4 motion sequence, in which four blades move backward while two blades move forward. A proof-of-principle experiment was performed to investigate the effects of tissue elasticity, tissue heterogeneity, and the motion sequence on the transportation rate [mg/s], transportation efficiency [%], and transportation reliability [%]. The mean transportation rate and reliability was highest for the 9 wt% gelatine phantoms at 4.21 ± 0.74 mg/s and the 1–5 sequence at 100%, respectively. The prototype has shown that the friction-based transportation principle has the potential of becoming a viable and reliable alternative to aspiration as a transportation method within MIS.

The Long-Term Efficacy of Radiofrequency Ablation Versus Laparoscopic Hepatectomy for Small Hepatocellular Carcinoma in East Asia: A Systematic Review and Meta-Analysis

Context: Hepatocellular carcinoma (HCC) is a common malignant cancer and the second leading cause of cancer-related deaths around the world. Radiofrequency ablation (RFA) and laparoscopic hepatectomy (LH) have been adopted for the treatment of HCC. The aim of the meta-analysis was to explore the long-term efficacy of RFA compared with LH for small HCC (sHCC) patients in the East Asian population. Evidence Acquisition: We performed a systematic review and meta-analysis by the literature search on PubMed, Cochrane Library, EMBASE, Chinese Biological Medical Literature (CBM), Chinese National Knowledge Infrastructure (CNKI), and Wanfang from their inception until October 10, 2019, for comparing the long-term efficacy outcomes of RFA with LH. Results: Fourteen retrospective studies with 1,390 subjects were included in the meta-analysis. Compared with the LH-treated group, RFA could raise the local recurrence rate under median follow-up duration and reduce disease-free survival (DFS) rates at 1 - 3 years. However, it failed to affect 5-year overall survival (OS) and DFS rates. In the subgroup analyses, different RFA approaches had significantly higher local recurrence rates than the LH group. A similar effect on OS and DFS rates within five years for single early (≤ 3 cm) HCCs and on the 1- and 5-year DFS rates for nodules ≤ 5 cm were observed between the two groups, but RFA approaches could reduce the 3-y OS and DFS rates for single nodules ≤ 5 cm. The percutaneous radiofrequency ablation (PRFA) group had significantly lower 3- and 5-year OS and the 1- and 3-year DFS rates than the LH group, while no significant difference in OS and DFS rates in the laparoscopic radiofrequency ablation (LRFA) approach. The RFA approach improved the 3-year OS compared with the LH group in Japan, but reduced the 3-year OS and DFS rates within 3 years in China. Conclusions: Our results support that LH treating sHCC had a better long-term efficacy and a lower local recurrence rate than RFA in the East Asian population. Further high-quality prospective studies are required to confirm the long-term efficacy.

Laparoscopic repeat liver resection

Recurrence of liver cancers inside the liver are often treated with liver resection (LR). However, increased risks of complications and conversion during operation were reported in laparoscopic repeat LR (LRLR). The indication is still controversial. One multi-institutional propensity score matching analysis of LRLR vs open repeat LR for hepatocellular carcinoma, two propensity score matching analyses for colorectal metastases, and two meta-analyses including hepatocellular carcinoma, intrahepatic cholangiocarcinoma, metastases, and other tumors have been reported to date. LRLR was reported with better to comparable short-term and similar long-term outcomes. Furthermore, the shorter operation time and the smaller amount of intraoperative bleeding for LRLR was reported for the patients who had undergone laparoscopic rather than open LR as an earlier procedure. The speculations are presented, that complete dissection of adhesion can be dodged and laparoscopic minor repeated LR can minimize the liver functional deterioration in cirrhotic patients. LRLR, as a powerful local therapy, could contribute to the long-term outcomes of those with deteriorated liver function. However, the procedure is now in its developing stage worldwide and further accumulation of experiences and evaluation are needed.

Is minimally invasive surgery of lesions in the right superior segments of the liver justified? A multi-institutional study of 245 patients

BACKGROUND

Controversy exists regarding the safety and feasibility of minimally invasive resection for lesions in segments 7 or 8. We compare outcomes of minimally invasive surgery (MIS) and Open parenchymal sparing liver resections at two high-volume centers.

METHODS

From 2003 to 2016 we identified patients who underwent MIS or Open resections for lesions in segments 7 or 8 at two institutions (MSKCC and SGH). Outcomes were compared using univariate and multivariate analyses.

RESULTS

Two-hundred and forty-five patients underwent resection of lesions in segments 7 or 8 (MIS 30% and Open 70%). Compared to the Open group, the MIS group had longer operative time (223 ± 88 vs 188 ± 72 minutes, P = .003), lower blood loss (297 ± 287 vs 448 ± 670 mL, P = .03), and shorter mean length of stay (5.2 ± 7.4 vs 8.3 ± 11.7 days, P < .001), which remained significant on multivariate analysis. No differences in Pringle time, rate of postoperative complications, or R0 resections were detected.

CONCLUSIONS

With appropriately selected patients treated by experienced MIS hepatopancreatobiliary surgeons, MIS resection of segments 7 or 8 is safe with similar rates of complications and R0 resections, with significantly less blood loss and shorter length of stay.

Laparoscopic Versus Open Left Lateral Segmentectomy for Large Hepatocellular Carcinoma: A Propensity Score-Matched Analysis

BACKGROUND

With the advancement of endoscopic technology, laparoscopic liver resection has become the standard procedure for left lateral segmentectomy. The aim of this study was to compare perioperative and oncological outcomes between laparoscopic and open left lateral segmentectomy for hepatocellular carcinoma (HCC) >5 cm.

PATIENTS AND METHODS

A total of 66 patients underwent left lateral segmentectomy for HCC (>5 cm) during the period spanning between 2013 and 2015. To overcome selection bias, 1:3 match using propensity score-matched analysis was performed between laparoscopic and open liver resection.

RESULTS

Relatively smaller tumor size (6.0 vs. 7.0 cm; P=0.030) and more frequent incidence of complete tumor capsule (93.3% vs. 58.8%; P=0.013) were observed in the laparoscopic group compared with the open group before matching. Although the longer operation time (195 vs. 150 min; P=0.022) was consumed in the laparoscopic procedure after matching, the laparoscopic group had shorter postoperative hospital stay (6 vs. 7 d; P=0.002) and less blood loss volume (50 vs. 100 mL; P=0.022). The Pringle maneuver for hepatic inflow occlusion was more likely to be applied in patients who underwent open surgery. The incidence of postoperative complication seemed to be lower in the laparoscopic group (6.7%) compared with that in the open group (11.8%) before matching. On the basis of propensity score-matched analysis, the complication rates were comparable between the 2 groups (7.1% vs. 6.7%, P=0.953). No difference in the 1-year and 3-year overall and recurrence-free survival rates was found between the laparoscopic and open groups.

CONCLUSION

Laparoscopic left lateral segmentectomy for large HCC patients showed better perioperative outcomes and equivalent oncologic outcomes as the open procedure, providing evidence for considering as a standard laparoscopic practice through careful selection.

Laparoscopic Liver Resection: A South American Experience with 2887 Cases

BACKGROUND

Laparoscopic liver resections (LLR) have been increasingly performed in recent years. Most of the available evidence, however, comes from specialized centers in Asia, Europe and USA. Data from South America are limited and based on single-center experiences. To date, no multicenter studies evaluated the results of LLR in South America. The aim of this study was to evaluate the experience and results with LLR in South American centers.

METHODS

From February to November 2019, a survey about LLR was conducted in 61 hepatobiliary centers in South America, composed by 20 questions concerning demographic characteristics, surgical data, and perioperative results.

RESULTS

Fifty-one (83.6%) centers from seven different countries answered the survey. A total of 2887 LLR were performed, as follows: Argentina (928), Brazil (1326), Chile (322), Colombia (210), Paraguay (9), Peru (75), and Uruguay (8). The first program began in 1997; however, the majority (60.7%) started after 2010. The percentage of LLR over open resections was 28.4% (4.4-84%). Of the total, 76.5% were minor hepatectomies and 23.5% major, including 266 right hepatectomies and 343 left hepatectomies. The conversion rate was 9.7%, overall morbidity 13%, and mortality 0.7%.

CONCLUSIONS

This is the largest study assessing the dissemination and results of LLR in South America. It showed an increasing number of centers performing LLR with the promising perioperative results, aligned with other worldwide excellence centers.

Pure Laparoscopic Versus Open Left Hepatectomy Including the Middle Hepatic Vein for Living Donor Liver Transplantation

Pure laparoscopic donor hepatectomy (PLDH) has become increasingly accepted in the era of minimally invasive surgeries. However, the outcomes of pure laparoscopic donor left hepatectomy (PLDLH) are relatively less known than for left lateral sectionectomy or right hepatectomy. This study aimed to report our experience with and the outcomes of PLDLH including the middle hepatic vein (MHV) and to compare these outcomes with conventional donor left hepatectomy (CDLH). The medical records of living liver donors between January 2010 and January 2018 at Seoul National University Hospital were retrospectively reviewed. Donors who underwent left hepatectomy including the MHV were included. To minimize selection bias, donors who underwent CDLH after the initiation of the PLDH program were excluded. Finally, there were 18 donors who underwent CDLH and 8 who underwent PLDLH. The median (interquartile range [IQR]) warm ischemia time (11 [10-16] minutes versus 4 [2-7] minutes; P = 0.001) was longer in the PLDLH group than the CDLH group. The total operation time (333 [281-376] minutes versus 265 [255-308] minutes; P = 0.09) and time to remove the liver (245 [196-276] minutes versus 182 [172-205] minutes; P = 0.08) were also longer in PLDLH although not statistically significant. The length of postoperative hospital stay was significantly shorter in the PLDLH group (7 [7-8] days versus 9 [8-10] days; P = 0.01). There were no postoperative complications in the PLDLH group. The rate of complications in recipients was similar in both groups. In conclusion, PLDLH including the MHV appears to be safe and feasible. Further analysis including longterm outcomes is needed.

Laparoscopic repeat liver resection for hepatocellular carcinoma: a multicentre propensity score-based study

BACKGROUND

In the absence of randomized controlled data and even propensity-matched data, indications for, and outcomes of, laparoscopic repeat liver resection for hepatocellular carcinoma (HCC) remain uncertain. This study aimed to clarify the current indications for laparoscopic repeat liver resection for HCC, and to evaluate outcomes.

METHODS

Forty-two liver surgery centres around the world registered patients who underwent repeat liver resection for HCC. Patient characteristics, preoperative liver function, tumour characteristics, surgical method, and short- and long-term outcomes were recorded.

RESULTS

Analyses showed that the laparoscopic procedure was generally used in patients with relatively poor performance status and liver function, but favourable tumour characteristics. Intraoperative blood loss (mean(s.d.) 254(551) versus 748(1128) ml; P < 0·001), duration of operation (248(156) versus 285(167) min; P < 0·001), morbidity (12·7 versus 18·1 per cent; P = 0·006) and duration of postoperative hospital stay (10·1(14·3) versus 11·8(11·8) days; P = 0·013) were significantly reduced for laparoscopic compared with open procedures, whereas survival time was comparable (median 10·04 versus 8·94 years; P = 0·297). Propensity score matching showed that laparoscopic repeat liver resection for HCC resulted in less intraoperative blood loss (268(730) versus 497(784) ml; P = 0·001) and a longer operation time (272(187) versus 232(129); P = 0·007) than the open approach, and similar survival time (12·55 versus 8·94 years; P = 0·086).

CONCLUSION

Laparoscopic repeat liver resection is feasible in selected patients with recurrent HCC.

Clinical outcomes of laparoscopic versus open right hepatectomy for liver tumors: A meta-analysis

BACKGROUND

Laparoscopic right hepatectomy (LRH) is one of the most challenging procedures. Right liver resections have been always performed in open procedure and open right hepatectomy (ORH) was initially considered as routine way. Moreover, it is unclear how beneficial the minimally invasive technique is to patients; thus, we conducted a meta-analysis to acquire a more reliable conclusion about the feasibility and safety of LRH compared with ORH.

METHODS

We comprehensively searched the electronic databases of PubMed, Embase, and the Cochrane Library using the key words. Meta-analysis was performed using the Review Manager, with results expressed as odds ratio and weighted mean difference with 95% confidence intervals. The fixed-effect model was selected initially if high heterogeneity was not present between the studies; otherwise, the randomized-effect model was used. Subgroup analysis was performed based on different surgical methods of pure laparoscopic operation or hand-assisted operation.

RESULTS

Seven studies with 467 patients were included. In the overall analysis, less intraoperative blood loss (MD = -155.17; 95% CI, -238.89, -71.45; P = .0003) and a shorter length of stay (MD = -4.45; 95% CI, -5.84, -3.07; P < .00001) were observed in the LRH group compared to the ORH group. There were fewer overall complications (OR = 0.30; 95% CI, 0.10, 0.90; P = 0.03) and severe complications (OR = 0.24; 95% CI, 0.10, 0.58; P = .002;) in the LRH group than in the ORH group. The disadvantage of LRH was the longer operative time (MD = 49.39; 95% CI, 5.33, 93.45; P = .03). No significant difference was observed between the 2 groups in portal occlusion, rate of R0 resection, transfusion rate, mild complications, and postoperative mortality. In the subgroup analysis, intraoperative blood loss was significantly lower in the pure LRH group and hand-assist LRH group compared with ORH group. Length of stay was shorter by use of pure LRH and hand-assisted LRH manners than ORH. The incidence rate of complications was lower in the pure LRH group than in the ORH group. In contrast, there was no significant difference between hand-assisted LRH group and ORH group.

CONCLUSION

Compared to ORH, LRH has short-term surgical advantages and leads to a shorter recovery time in selected patients. We speculate that the operative time of LRH is closer with ORH. Overall, LRH can be considered a feasible choice in routine clinical practice with experienced surgeons, although more evidence is needed to make a definitive conclusion.

Systematic review and meta-analysis of local ablative therapies for resectable colorectal liver metastases

INTRODUCTION

Local ablative therapies (LAT) have shown positive but heterogenous outcomes in the treatment of colorectal liver metastases (CRLM). The aim of this systematic review is to evaluate LAT and compare them with surgical resection.

METHODS

In accordance with PRISMA guidelines, Medline, EMBASE, Cochrane and Web of Science databases were searched for reports published before January 2019. We included papers assessing radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation (CA) and electroporation (IRE) treating resectable CRLM with curative intention. We evaluated LAT related complications and oncological outcomes as tumour progression (LTP), disease-free survival (DFS) and overall survival (OS).

RESULTS

The literature search yielded 6767 records; 20 papers (860 patients) were included. No included studies related mortality with LAT. Median adverse events percentage was 7%: (8% RFA;7% MWA). Median 3y-DFS was 32% (24% RFA; 60% MWA); 5y-DFS was 27%: (18% RFA; 38.5% MWA). Median 3y-OS was 59% (60% RFA; 70% MWA; 34% CA), 5y-OS was 44.5% (43% RFA; 55% MWA; 20% CA). Surgical resection showed decreased LTP, improved DFS and OS than those reported with LAT, with RFA accounting for reduced 1y-DFS (RR 0.83, 95%CI 0.71-0.98), 3y-DFS (RR 0.5, 95%CI 0.33-0.76), 5y-DFS (RR 0.53, 95%CI 0.28-0.98) and 5y-OS (RR 0.76, 95%CI 0.58-0.98) in comparison with surgical resection.

CONCLUSIONS

Low quality evidence suggests that both RFA and MWA seem superior to CA. MWA presents similar adverse events when compared to RFA with a possible increase in DFS and OS. Surgical resection still seems to provide superior DFS and OS in comparison with LAT.

Early experience of laparoscopic liver resection: A single institution experience with 37 consecutive cases

Backgrounds/Aims

Laparoscopic liver resection (LLR) has evolved and broadened in scope. While open liver resections are currently being performed safely in our hospital, LLRs are being implemented in fewer cases. The aim of this study was to review our initial experience in LLR to assess early outcomes of the procedure.

Methods

A retrospective chart review was conducted for 37 patients who underwent laparoscopic liver resections for various indications between January 2014 and July 2017 by a single surgeon who had performed 161 open liver resections and 50 live donor hepatectomies during the same period.

Results

Of 37 laparoscopic liver resections performed, male to female ratio was 23 to 4. Their mean age was 61.4 years. There were 13 cases of wedge resections, 7 cases of left lateral sectionectomy, 9 cases of left hepatectomy, and 8 cases of right hepatectomy. Pathology included hepatocellular carcinoma (n=20), cholangiocarcinoma (n=3), intrahepatic duct stones (n=6), metastatic liver carcinoma (n=6), primary neuroendocrine tumor of liver (n=1), and huge hemangioma (n=1). The mean operation time was 174.7 minutes (range, 40–410 minutes). Mean blood loss was 200.5 ml (range, 10–2200 ml). There were no open-conversion cases. There were no intraoperative or postoperative complications except that a case of severe portal vein stenosis in the laparoscopic right hepatectomy occurred postoperatively. The patient underwent reoperation (portal vein resection and anastomosis, stenting). The mean hospital stay was 8.7 days (range, 2–44 days).

Conclusions

Even though our experience in laparoscopic liver resection is still developing, our results are comparable to those of other studies. Therefore, an experienced surgeon in performing open liver resection should be able to perform the laparoscopic liver resection safely.

Comparison of Projective Augmented Reality Concepts to Support Medical Needle Insertion

Augmented reality (AR) is a promising tool to improve instrument navigation in needle-based interventions. Limited research has been conducted regarding suitable navigation visualizations. In this work, three navigation concepts based on existing approaches were compared in a user study using a projective AR setup. Each concept was implemented with three different scales for accuracy-to-color mapping and two methods of navigation indicator scaling. Participants were asked to perform simulated needle insertion tasks with each of the resulting 18 prototypes. Insertion angle and insertion depth accuracies were measured and analyzed, as well as task completion time and participants' subjectively perceived task difficulty. Results show a clear ranking of visualization concepts across variables. Less consistent results were obtained for the color and indicator scaling factors. Results suggest that logarithmic indicator scaling achieved better accuracy, but participants perceived it to be more difficult than linear scaling. With specific results for angle and depth accuracy, our study contributes to the future composition of improved navigation support and systems for precise needle insertion or similar applications.