Laparoscopic liver resection for hepatocellular carcinoma complicated with significant portal hypertension:A propensity score-matched survival analysis

Background: Significant portal hypertension(SPH) is a relative contraindication for patients with resectable hepatocellular carcinoma(HCC). However, increasing evidence indicates that liver resection is feasible for HCC patients with SPH. Methods: HCC patients with cirrhosis who underwent laparoscopic liver resection(LLR) in two centers from January 2013 to April 2018 were included. Surgical and survival outcomes were analyzed to explore potential prognostic factors. Propensity score matching(PSM) analysis was performed to minimize bias. Results: A total of 165 patients were divided into two groups based on the presence(SPH, n = 76) or absence(non-SPH, n = 89) of SPH. Patients in the SPH group had longer operative time, more blood loss, and more advanced TNM stage than patients in the non-SPH group( P < 0.05). However, there were no significant differences in the postoperative 90-day mortality rate( n = 0), overall postoperative complications(47.4% vs. 41.6%, P = 0.455), Clavien-Dindo classification( P = 0.347), conversion to open surgery(9.2% vs. 6.7%, P = 0.557), or length of hospitalization(16 vs. 15 days, P = 0.203) between the SPH and non-SPH groups before PSM. Similar results were obtained after PSM. The 1-, 3-, and 5-year overall survival(OS) and recurrence-free survival rates in the SPH group were not significantly different from those in the non-SPH group both before and after PSM(log-rank P > 0.05). After PSM, alpha-fetoprotein(AFP) ≥ 400 μg/L [hazard ratio(HR) = 4.71, 95% confidence interval(CI): 2.69-8.25], ascites(HR = 2.18, 95% CI: 1.30-3.66), American Society of Anesthesiologists(ASA) classification(Ⅲ vs. Ⅱ)(HR = 2.13, 95% CI: 1.11-4.07) and tumor diameter > 5 cm(HR = 3.91, 95% CI: 2.02-7.56) independently predicted worse OS. Conclusions: LLR for patients with HCC complicated with SPH appears feasible at the price of increasing operative time and blood loss. AFP, ascites, ASA classification and tumor diameter may predict the prognosis of HCC complicated with SPH after LLR.

Laparoscopic liver resection under hemihepatic vascular inflow occlusion using the lowering of hilar plate approach

BACKGROUND： With advances in technology, laparoscopic liver resection is widely accepted. Laparoscopic liver resection under hemihepatic vascular inflow occlusion has advantages over the conventional total hepatic inflow occlusion using the Pringle＇s maneuver, especially in patients with cirrhosis.METHOD： From November 2011 to August 2012, eight consecutive patients underwent laparoscopic liver resection under hemihepatic vascular inflow occlusion using the lowering of hilar plate approach with biliary bougie assistance.RESULTS： The types of liver resection included right hepatectomy（n1）, right posterior sectionectomy（n1）, left hepatectomy and common bile duct exploration（n1）, segment 4b resection（n1）, left lateral sectionectomy（n2）, and wedge resection（n2）. Four patients underwent right and 4 left hemihepatic vascular inflow occlusion. Four patients had cirrhosis. The mean operation time was 176.3 minutes. The mean time taken to achieve hemihepatic vascular inflow occlusion was 24.3minutes. The mean duration of vascular inflow occlusion was54.5 minutes. The mean intraoperative blood loss was 361 mL.No patient required blood transfusion. Postoperatively, one patient developed bile leak which healed with conservative treatment. No postoperative liver failure and mortality occurred. The mean hospital stay of the patients was 7 days.CONCLUSION： Our technique of hemihepatic vascular inflow vascular occlusion using the lowering of hilar plate approachwas safe, and it improved laparoscopic liver resection by minimizing blood loss during liver parenchymal transection.

Laparoscopic liver resection for colorectal liver metastases—shortand long-term outcomes:A systematic review

BACKGROUND For well-selected patients and procedures,laparoscopic liver resection(LLR)has become the gold standard for the treatment of colorectal liver metastases(CRLM)when performed in specialized centers.However,little is currently known concerning patient-related and peri-operative factors that could play a role in survival outcomes associated with LLR for CRLM.AIM To provide an extensive summary of reported outcomes and prognostic factors associated with LLR for CRLM.METHODS A systematic search was performed in PubMed,EMBASE,Web of Science and the Cochrane Library using the keywords“colorectal liver metastases”,“laparoscopy”,“liver resection”,“prognostic factors”,“outcomes”and“survival”.Only publications written in English and published until December 2019 were included.Furthermore,abstracts of which no accompanying full text was published,reviews,case reports,letters,protocols,comments,surveys and animal studies were excluded.All search results were saved to Endnote Online and imported in Rayyan for systematic selection.Data of interest were extracted from the included publications and tabulated for qualitative analysis.RESULTS Out of 1064 articles retrieved by means of a systematic and grey literature search,77 were included for qualitative analysis.Seventy-two research papers provided data concerning outcomes of LLR for CRLM.Fourteen papers were eligible for extraction of data concerning prognostic factors affecting survival outcomes.Qualitative analysis of the collected data showed that LLR for CRLM is safe,feasible and provides oncological efficiency.Multiple research groups have reported on the short-term advantages of LLR compared to open procedures.The obtained results accounted for minor LLR,as well as major LLR,simultaneous laparoscopic colorectal and liver resection,LLR of posterosuperior segments,twostage hepatectomy and repeat LLR for CRLM.Few research groups so far have studied prognostic factors affecting long-term outcomes of LLR for CRLM.CONCLUSION In experienced hands,LLR for CRLM provides good short-and long-term outcomes,independent of the complexity of the procedure.

Four-year experience with more than 1000 cases of total laparoscopic liver resection in a single center

BACKGROUND Laparoscopic liver resection(LLR)has become a safe surgical procedure that needs additional summarization.AIM To review 4 years of total LLR surgeries,exceeding 1000 cases,which were performed at a single center.METHODS Patients who underwent LLR at West China Hospital of Sichuan University between January 2015 and December 2018 were identified.Surgical details,including the interventional year,category of liver disease,and malignant liver tumors prognosis,were evaluated.The learning curve for LLR was evaluated using the cumulative sum method.The Kaplan-Meier method was used to perform survival analysis.RESULTS Ultimately,1098 patients were identified.Hepatocellular carcinoma(HCC)was the most common disease that led to the need for LLR at the center(n=462,42.08%).The average operation time was 216.94±98.51 min.The conversion rate was 1.82%(20/1098).The complication rate was 9.20%(from grade II to V).The 1-year and 3-year overall survival rates of HCC patients were 89.7%and 81.9%,respectively.The learning curve was grouped into two phases for local resection(cases 1-106 and 107-373),three phases for anatomical segmentectomy(cases 1-44,45-74 and 75-120),and three phases for hemihepatectomy(cases 1-17,18-48 and CONCLUSION LLR may be considered a first-line surgical intervention for liver resection that can be performed safely for a variety of primary,secondary,and recurrent liver tumors and for benign diseases once technical competence is proficiently attained.

Indications of pro-inflammatory cytokines in laparoscopic and open liver resection for early-stage hepatocellular carcinoma

Background:Our clinical practice of laparoscopic liver resection(LLR)had achieved better short-term and long-term benefits for patients with hepatocellular carcinoma(HCC)over open liver resection(OLR),but the underlying mechanisms are not clear.This study was to find out whether systemic inflammation plays an important role.Methods:A total of 103 patients with early-stage HCC under liver resection were enrolled(LLR group,n=53;OLR group,n=50).The expression of 9 inflammatory cytokines in patients at preoperation,postoperative day 1(POD1)and POD7 was quantified by Luminex Multiplex assay.The relationships of the cytokines and the postoperative outcomes were compared between LLR and OLR.Results:Seven of the circulating cytokines were found to be significantly upregulated on POD1 after LLR or OLR compared to their preoperative levels.Compared to OLR,the POD1 levels of granulocytemacrophage colony-stimulating factor(GM-CSF),interleukin-6(IL-6),IL-8,and monocyte chemoattractant protein-1(MCP-1)in the LLR group were significantly lower.Higher POD1 levels of these cytokines were significantly correlated with longer operative time and higher volume of blood loss during operation.The levels of these cytokines were positively associated with postoperative liver injury,and the length of hospital stay.Importantly,a high level of IL-6 at POD1 was a risk factor for HCC recurrence and poor disease-free survival after liver resection.Conclusions:Significantly lower level of GM-CSF,IL-6,IL-8,and MCP-1 after liver resection represented a milder systemic inflammation which might be an important mechanism to offer better short-term and long-term outcomes in LLR over OLR.

Robotic versus laparoscopic liver resection for huge (≥10 cm) liver tumors: an international multicenter propensity-score matched cohort study of 799 cases

Background:The use of laparoscopic(LLR)and robotic liver resections(RLR)has been safely performed in many institutions for liver tumours.A large scale international multicenter study would provide stronger evidence and insight into application of these techniques for huge liver tumours≥10 cm.Methods:This was a retrospective review of 971 patients who underwent LLR and RLR for huge(≥10 cm)tumors at 42 international centers between 2002-2020.Results:One hundred RLR and 699 LLR which met study criteria were included.The comparison between the 2 approaches for patients with huge tumors were performed using 1:3 propensity-score matching(PSM)(73 vs.219).Before PSM,LLR was associated with significantly increased frequency of previous abdominal surgery,malignant pathology,liver cirrhosis and increased median blood.After PSM,RLR and LLR was associated with no significant difference in key perioperative outcomes including media operation time(242 vs.290 min,P=0.286),transfusion rate rate(19.2%vs.16.9%,P=0.652),median blood loss(200 vs.300 mL,P=0.694),open conversion rate(8.2%vs.11.0%,P=0.519),morbidity(28.8%vs.21.9%,P=0.221),major morbidity(4.1%vs.9.6%,P=0.152),mortality and postoperative length of stay(6 vs.6 days,P=0.435).Conclusions:RLR and LLR can be performed safely for selected patients with huge liver tumours with excellent outcomes.There was no significant difference in perioperative outcomes after RLR or LLR.

International experts consensus guidelines on robotic liver resection in 2023

The robotic liver resection(RLR)has been increasingly applied in recent years and its benefits shown in some aspects owing to the technical advancement of robotic surgical system,however,controversies still exist.Based on the foundation of the previous consensus statement,this new consensus document aimed to update clinical recommendations and provide guidance to improve the outcomes of RLR clinical practice.The guideline steering group and guideline expert group were formed by 29 international experts of liver surgery and evidence-based medicine(EBM).Relevant literature was reviewed and analyzed by the evidence evaluation group.According to the WHO Handbook for Guideline Development,the Guidance Principles of Development and Amendment of the Guidelines for Clinical Diagnosis and Treatment in China 2022,a total of 14 recommendations were generated.Among them were 8 recommendations formulated by the GRADE method,and the remaining 6 recommendations were formulated based on literature review and experts’opinion due to insufficient EBM results.This international experts consensus guideline offered guidance for the safe and effective clinical practice and the research direction of RLR in future.

Single incision laparoscopic liver resection： a case report

Laparoscopic procedure as a minimally invasive surgery has been introduced into many abdominal surgeries. Smaller incisions of the abdominal wall reduce postoperative pain and the risk of wound complications, and provide an excellent cosmetic result compared with open surgery. Natural orifice transluminal endoscopic surgery （NOTES）, a no-scar surgery, is a hot spot of modern surgery. However,

Pure Laparoscopic Liver Resection for Malignant Liver Tumor： Anatomic Resection Versus Nonanatomic Resection

Background： Laparoscopic liver resection （LLR） has been considered to be safe and feasible. However, few studies focused on the comparison between the anatomic and nonanatomic LLR. Therefore, the purpose of this study was to compare the perioperative factors and outcomes of the anatomic and nonanatomic LLR, especially the area of liver parenchymal transection and blood loss per unit area. Methods： In this study, surgical and oncological data of patients underwent pure LLR procedures for malignant liver tumor were prospectively collected. Blood loss per unit area of liver parenchymal transection was measured and considered as an important parameter. All procedures were conducted by a single surgeon. Results： During nearly 5 years, 84 patients with malignant liver tumor received a pure LLR procedure were included. Among them, 34 patients received anatomic LLR and 50 received nonanatomic LLR, respectively. Patients of the two groups were similar in terms of demographic features and tumor characteristics, despite the tumor size was significantly larger in the anatomic LLR group than that in the nonanatomic LLR group （4.77 ± 2.57 vs. 2.87 ± 2.10 cm, P = 0.001）. Patients who underwent anatomic resection had longer operation time （364.09 ± 131.22 vs. 252.00±135.21 min, P 〈 0.001） but less blood loss per unit area （7.85 ± 7.17 vs. 14.17 ± 10.43 ml/cm2, P = 0.018）. Nonanatomic LLR was associated with more blood loss when the area of parenchymal transection was equal to the anatomic LLR. No mortality occurred during the hospital stay and 30 days alter the operation. Moreover, there was no difference in the incidence of postoperative complications. The disease-free and overall survival rates showed no significant differences between the anatomic LLR and nonanatomic LLR groups. Conclusions： Both anatomic and nonanatomic pure LLR are safe and feasible. Measuring the area of parenchymal transection is a simple and effective method to estimate the outcomes of the liver resection surgery＇. Blood loss per unit area is an important parameter which is comparable between the anatomic LLR and nonanatomic LLR groups.

Case report of the fourth laparoscopic liver resection and review of repeat laparoscopic resection for recurrent hepatocellular carcinoma in cirrhotic liver

A 73-year-old woman with liver cirrhosis caused by hepatitis C virus(HCV)underwent treatment of three hepatocellular carcinomas(HCCs)in liver segment 4,following three previous laparoscopic liver resections(LLRs)over 73 months.Contrast-enhanced computed tomography showed three 0.5-1.2 cm HCCs deep within the portal territories of subsegments 4a and 4b.The patient underwent laparoscopic resection of 4a and 4b,with the preservation of the portal branch to 4c,after minimal adhesiolysis around segment 4.The operation lasted 284 min,there was 50 mL of intra-operative bleeding and her recovery was uneventful.She was well,had experienced no recurrence and was HCV-negative,after taking oral anti-HCV therapy,21 months later.LLR is associated with fewer adhesions after surgery and requires less adhesiolysis,because the laparoscope and forceps can be used in the small spaces between adhesions.The present patient underwent four LLRs over 6 years without severe deterioration of liver functional reserve.LLR is a useful localized therapy,which can be performed repeatedly and may prolong the survival of patients with multicentric metachronous HCCs.

Laparoscopic liver resection in the cirrhotic patient

Aim:The adoption of laparoscopic liver resection has been expansive in the last 2 decades with the exception of cirrhotic patients.The current study examines the outcomes of our cirrhotic resections to determine the potential limitations of this technique.Methods:Retrospective analysis of 114 cirrhotic patients.Seventy-five(65.8%)laparoscopic resections were compared to 39 open resections.Seventy-six(66.7%)resections in the series were minor resections(less than 3 segments).Surgical approach and extent of resection were analyzed using student’s t test and regression multivariate analysis with SAS.Results:The laparoscopic group had lower operative times(2.4 vs.4.8 h;P<0.001),blood loss(250 vs.609 mL;P<0.001),length of stay(4.4 vs.10.1 days;P=0.013)a nd c omplications(28%vs.48%;P=0.028).Subset analysis by technique and extent of resection identified the laparoscopic group lost the advantage in blood loss and lengths of stay when utilized in major resections.Multivariate regression analysis for blood loss further confirmed open resection(P=0.014)a nd major resection(P=0.026)a s significant i ndicators of bleeding and transfusion.Conclusion:Laparoscopic liver resection in cirrhotic patients is safe and efficacious.However,the significant variability in outcomes for major resections in cirrhotics leads us to recommend further examination of the learning curve and significant caution in the selection of cirrhotics requiring major hepatic resections.

Indications and technique for laparoscopic liver resection in patients with hepatocellular carcinoma and liver cirrhosis

Liver resection is the preferred initial treatment option for solitary or limited multifocal hepatocellular carcinoma(HCC).However,because of the characteristics of HCC,including its high recurrence rate and the frequent presence of chronic hepatitis and cirrhosis,both curability and invasiveness must be considered when selecting a treatment for HCC.Laparoscopic liver resection(LLR)is minimally invasive and increasingly performed worldwide as a curative surgical option for treatment of liver tumors.The 2014 International Consensus Conference on LLR concluded that minor LLRs are now standard practice.Meta-analyses suggest that,as compared with open hepatectomy,LLR for patients with HCC,including those with cirrhosis,resulted in less blood loss,lower postoperative hospitalization rates,and similar oncological outcomes.Although candidates for this procedure should be carefully evaluated,LLR appears to be a feasible option for treatment of HCC with liver cirrhosis.This review describes the indications for LLR in this patient subgroup and offers guidance on appropriate surgical technique.

Laparoscopic left liver lobectomy for hepatocellular carcinoma in a cirrhotic patient： a video report

We present a video case of a 51-year-old man admitted to our surgical and liver transplantation unit for hepatocellular cancer（HCC）. Patient has a HCV cirrhosis with portal hypertension and esophageal varices F1. Child Pugh score was B7 and model of end staged liver disease（MELD） was 11. Body mass index（BMI） was 26.7 and ASA score was 2. No previous abdominal surgery. According with our multidisciplinary group we suggest a laparoscopic left lobectomy for the patient. Pringle manoeuvre was not performed. Operation time was 193 min and blood loss estimation was 100 cc. No transfusion was required. Postoperative course was uneventful, grade I of Clavien-Dindo Classification. Patient was discharged in day 8. In our experience laparoscopic resection in cirrhotic liver should be performed in selected patients and in an experienced team.

Using the win ratio to compare laparoscopic versus open liver resection for colorectal cancer liver metastases

Background:We sought to assess the overall benefit of laparoscopic versus open hepatectomy for treatment of colorectal liver metastases(CRLMs)using the win ratio,a novel methodological approach.Methods:CRLM patients undergoing curative-intent resection in 2001-2018 were identified from an international multi-institutional database.Patients were paired and matched based on age,number and size of lesions,lymph node status and receipt of preoperative chemotherapy.The win ratio was calculated based on margin status,severity of postoperative complications,90-day mortality,time to recurrence,and time to death.Results:Among 962 patients,the majority underwent open hepatectomy(n=832,86.5%),while a minority underwent laparoscopic hepatectomy(n=130,13.5%).Among matched patient-to-patient pairs,the odds of the patient undergoing laparoscopic resection“winning”were 1.77[WR:1.77,95%confidence interval(CI):1.42-2.34].The win ratio favored laparoscopic hepatectomy independent of low(WR:2.94,95%CI:1.20-6.39),medium(WR:1.56,95%CI:1.16-2.10)or high(WR:7.25,95%CI:1.13-32.0)tumor burden,as well as unilobar(WR:1.71,95%CI:1.25-2.31)or bilobar(WR:4.57,95%CI:2.36-8.64)disease.The odds of“winning”were particularly pronounced relative to short-term outcomes(i.e.,90-day mortality and severity of postoperative complications)(WR:4.06,95%CI:2.33-7.78).Conclusions:Patients undergoing laparoscopic hepatectomy had 77%increased odds of“winning”.Laparoscopic liver resection should be strongly considered as a preferred approach to resection in CRLM patients.

Advances and challenges in laparoscopic surgery in the management of hepatocellular carcinoma

Hepatocellular carcinoma is the fifth most common malignancy and the third most common cause of cancer-related mortality worldwide. From the wide variety of treatment options, surgical resection and liver transplantation are the only therapeutic ones. However, due to shortage of liver grafts, surgical resection is the most common therapeutic modality implemented. Owing to rapid technological development, minimally invasive approaches have been incorporated in liver surgery. Liver laparoscopic resection has been evaluated in comparison to the open technique and has been shown to be superior because of the reported decrease in surgical incision length and trauma, blood loss, operating theatre time, postsurgical pain and complications, R0 resection, length of stay, time to recovery and oral intake. It has been reported that laparoscopic excision is a safe and feasible approach with near zero mortality and oncologic outcomes similar to open resection. Nevertheless, current indications include solid tumors in the periphery < 5 cm, especially in segments Ⅱ through Ⅵ, while according to the consensus laparoscopic major hepatectomy should only be performed by surgeons with high expertise in laparoscopic and hepatobiliary surgery in tertiary centers. It is necessary for a surgeon to surpass the 60-cases learning curve observed in order to accomplish the desirable outcomes and preserve patient safety. In this review, our aim is to thoroughly describe the general principles and current status of laparoscopic liver resection for hepatocellular carcinoma, as well as future prospects.

Current status of minimally invasive liver surgery for cancers

Hepatocellular carcinoma(HCC)patients have chronic liver disease with functional deterioration and multicentric oncogenicity.Liver surgeries for the patients should be planned on both oncological effects and sparing liver function.In colorectal patients with post-chemotherapy liver injury and multiple bilateral tumors,handling multiple tumors in a fragile/easy-to-bleed liver is an important issue.Liver surgery for biliary tract cancers is often performed as a resection of large-volume functioning liver with extensive lymphadenectomy and bile duct resection/reconstruction.Minimally invasive liver surgery(MILS)for HCC is applied with the advantages of laparoscopic for cases of cirrhosis or repeat resections.Small anatomical resections using the Glissonian,indocyanine greenguided,and hepatic vein-guided approaches are under discussion.In many cases of colorectal liver metastases,MILS is applied combined with chemotherapy owing to its advantage of better hemostasis.Two-stage hepatectomy and indocyanine green-guided tumor identification for multiple bilateral tumors are under discussion.In the case of biliary tract cancers,MILS with extensive lymphadenectomy and bile duct resection/reconstruction are developing.A robotassisted procedure for dissection of major vessels and handling fragile livers may have advantages,and well-simulated robot-assisted procedure may decrease the difficulty for biliary tract cancers.

Current status of laparoscopic repeat liver resection for hepatocellular carcinoma

Although liver resection(LR)is often adopted to recurrent hepatocellular carcinomas,risks of complications and conversion reportedly increase in laparoscopic repeat LR(LRLR).The indication is not agreed upon even with the recent advances of laparoscopic LR.We conducted an international propensity score matching study of LRLR and open repeat LR for hepatocellular carcinoma with 1,582 patients from 42 world centers.Propensity-score matched LRLR patients have smaller blood loss and longer operation time than open repeat LR patients.Median overall survival time was 8.94 years in open and 12.55 years in LRLR;although the difference was not significant,the P-value was 0.0855 and the better curve of LRLR is clearly separated from that of open.In our institution,we experienced 34 LRLR and 12 cases of three times or more repeat LR until 2019.There are no significant differences in operation time,blood loss,hospital stay,conversion,and morbidity rates among first,second,and third or higher laparoscopic LR,which is different from the open situation.However,postoperative bile leakage and intraoperative bleeding causing conversion did happen in the cases with repeat extended exposure of Glissonian pedicle.LRLR is feasible for selected patients.However,the procedure is under developing stage and further accumulation of experiences and evaluation are needed.

Repeat laparoscopic anatomical liver resection in a hepatocellular carcinoma patient:a case report

Anatomical resection(AR)has been reported to achieve better long-term outcomes than non-anatomical resection for the treatment of hepatocellular carcinoma(HCC).The surgical feasibility and oncological significance of laparoscopic AR(LAR),especially“subsegment resection”,“cone unit resection”,and repeat LAR for HCC,remain unproven.We present a 67-year-old patient with alcoholic liver cirrhosis and HCC who underwent full LAR three times,focusing on the technical aspects of the Glissonean approach.Repeating LAR for recurrent HCC could be a safe and feasible procedure.However,HCC recurred in the neighboring segment twice,even though pathological vascular invasion and marginal remnants were not confirmed.We should investigate the oncological significance and advancements in subsegmentectomy and cone unit resection,in the future.

Current status of laparoscopic repeat liver resection for recurrent hepatocellular carcinoma

Repeat liver resection(RLR)is an effective treatment approach for recurrent hepatocellular carcinoma(HCC)and can provide acceptable long-term outcomes in select patients.Recent randomized controlled trials comparing RLR with radiofrequency ablation revealed that the latter approach was associated with a higher rate of early recurrence compared with RLR.With recent advances in laparoscopic liver resection(LLR),RLR has been increasingly performed using laparoscopy.Several propensity score-matched studies reported that laparoscopic RLR achieved lower blood loss and shorter hospital stays compared to open RLR.However,laparoscopic RLR requires more advanced techniques because of adhesions formed after the previous liver resection,changes in anatomical landmarks,and deformity of the remnant liver.The recently described difficulty classification of laparoscopic RLR is based on five factors including type of previous liver resection(open or laparoscopic),number of previous liver resections,surgical procedure used in previous liver resections,tumor location in previous liver resections,and difficulty score of LLR for recurrent HCC.We reviewed the available literature to summarize available evidence suggesting that laparoscopic RLR might be considered a more minimally invasive surgical treatment approach for recurrent HCC as long as the indication for laparoscopic RLR is carefully determined.

Minimally invasive liver resection for huge(≥10cm)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.