Impact of Tumor Size on the Difficulty of Laparoscopic Major Hepatectomies: An International Multicenter Study

INTRODUCTION

Although tumor size (TS) is known to affect surgical outcomes in laparoscopic liver resection (LLR), its impact on laparoscopic major hepatectomy (L-MH) is not well studied. The objectives of this study were to investigate the impact of TS on the perioperative outcomes of L-MH and to elucidate the optimal TS cutoff for stratifying the difficulty of L-MH.

METHODS

This was a post-hoc analysis of 3008 patients who underwent L-MH at 48 international centers. A total 1396 patients met study criteria and were included. The impact of TS cutoffs was investigated by stratifying TS at each 10-mm interval. The optimal cutoffs were determined taking into consideration the number of endpoints which showed a statistically significant split around the cut-points of interest and the magnitude of relative risk after correction for multiple risk factors.

RESULTS

We identified 2 optimal TS cutoffs, 50 mm and 100 mm, which segregated L-MH into 3 groups. An increasing TS across these 3 groups (≤ 50 mm, 51-100 mm, > 100 mm), was significantly associated with a higher open conversion rate (11.2%, 14.7%, 23.0%, P < 0.001), longer operating time (median, 340 min, 346 min, 365 min, P = 0.025), increased blood loss (median, 300 ml,  ml, 400 ml, P = 0.002) and higher rate of intraoperative blood transfusion (13.1%, 15.9%, 27.6%, P < 0.001). Postoperative outcomes such as overall morbidity, major morbidity, and length of stay were comparable across the three groups.

CONCLUSION

Increasing TS was associated with poorer intraoperative but not postoperative outcomes after L-MH. We determined 2 TS cutoffs (50 mm and 10 mm) which could optimally stratify the surgical difficulty of L-MH.

Impact of liver cirrhosis and portal hypertension on minimally invasive limited liver resection for primary liver malignancies in the posterosuperior segments: An international multicenter study

INTRODUCTION

To assess the impact of cirrhosis and portal hypertension (PHT) on technical difficulty and outcomes of minimally invasive liver resection (MILR) in the posterosuperior segments.

METHODS

This is a post-hoc analysis of patients with primary malignancy who underwent laparoscopic and robotic wedge resection and segmentectomy in the posterosuperior segments between 2004 and 2019 in 60 centers. Surrogates of difficulty (i.e, open conversion rate, operation time, blood loss, blood transfusion, and use of the Pringle maneuver) and outcomes were compared before and after propensity-score matching (PSM) and coarsened exact matching (CEM).

RESULTS

Of the 1954 patients studied, 1290 (66%) had cirrhosis. Among the cirrhotic patients, 310 (24%) had PHT. After PSM, patients with cirrhosis had higher intraoperative blood transfusion (14% vs. 9.3%; p = 0.027) and overall morbidity rates (20% vs. 14.5%; p = 0.023) than those without cirrhosis. After coarsened exact matching (CEM), patients with cirrhosis tended to have higher intraoperative blood transfusion rate (12.1% vs. 6.7%; p = 0.059) and have higher overall morbidity rate (22.8% vs. 12.5%; p = 0.007) than those without cirrhosis. After PSM, Pringle maneuver was more frequently applied in cirrhotic patients with PHT (62.2% vs. 52.4%; p = 0.045) than those without PHT.

CONCLUSION

MILR in the posterosuperior segments in cirrhotic patients is associated with higher intraoperative blood transfusion and postoperative morbidity. This parameter should be utilized in the difficulty assessment of MILR.

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.

Validation of VIBe bleeding scale amongst hepatopancreatobiliary surgeons: results from an IHPBA survey

BACKGROUND

The Validated Intraoperative Bleeding (VIBe) Scale could be used to aid assessment of intraoperative bleeding and guide the use of hemostatic products. The aim of this survey was to determine if the VIBe scale would serve as a generalizable and relevant tool for hepatopancreatobiliary(HPB) surgeons and trainees.

METHODS

A standardized online VIBe training module was conducted on 67 respondents from 25 countries, after which they used the VIBe scale to score videos depicting different severities of intraoperative bleeding. Interobserver agreement was assessed using Kendall's coefficient of concordance.

RESULTS

Interobserver agreement was excellent amongst all respondents with a Kendall's W of 0.923. Sub-analyses showed a difference based on seniority and level of experience: Attendings/Consultants(0.947) vs Fellows/Residents(0.879); Increasing years of practice >10(0.952) vs <10 years practice(0.890). There was excellent concordance regardless of surgical volume, percentage of procedures performed minimally invasively, area of sub-specialty, and previous involvement with VIBe surveys.

CONCLUSION

This international survey in the field of HPB surgery across surgeons of various levels of experience showed that the VIBe scale could serve as an excellent tool to assess the severity of bleeding. This scale would also be useful in guiding the use and choice of hemostatic adjuncts to achieve hemostasis.

Risk Factors and Outcomes of Open Conversion During Minimally Invasive Major Hepatectomies: An International Multicenter Study on 3880 Procedures Comparing the Laparoscopic and Robotic Approaches

INTRODUCTION

Despite the advances in minimally invasive (MI) liver surgery, most major hepatectomies (MHs) continue to be performed by open surgery. This study aimed to evaluate the risk factors and outcomes of open conversion during MI MH, including the impact of the type of approach (laparoscopic vs. robotic) on the occurrence and outcomes of conversions.

METHODS

Data on 3880 MI conventional and technical (right anterior and posterior sectionectomies) MHs were retrospectively collected. Risk factors and perioperative outcomes of open conversion were analyzed. Multivariate analysis, propensity score matching, and inverse probability treatment weighting analysis were performed to control for confounding factors.

RESULTS

Overall, 3211 laparoscopic MHs (LMHs) and 669 robotic MHs (RMHs) were included, of which 399 (10.28%) had an open conversion. Multivariate analyses demonstrated that male sex, laparoscopic approach, cirrhosis, previous abdominal surgery, concomitant other surgery, American Society of Anesthesiologists (ASA) score 3/4, larger tumor size, conventional MH, and Institut Mutualiste Montsouris classification III procedures were associated with an increased risk of conversion. After matching, patients requiring open conversion had poorer outcomes compared with non-converted cases, as evidenced by the increased operation time, blood transfusion rate, blood loss, hospital stay, postoperative morbidity/major morbidity and 30/90-day mortality. Although RMH showed a decreased risk of conversion compared with LMH, converted RMH showed increased blood loss, blood transfusion rate, postoperative major morbidity and 30/90-day mortality compared with converted LMH.

CONCLUSIONS

Multiple risk factors are associated with conversion. Converted cases, especially those due to intraoperative bleeding, have unfavorable outcomes. Robotic assistance seemed to increase the feasibility of the MI approach, but converted robotic procedures showed inferior outcomes compared with converted laparoscopic procedures.

Impact of body mass index on perioperative outcomes of laparoscopic major hepatectomies

BACKGROUND

Data on the effect of body mass index on laparoscopic liver resections are conflicting. We performed this study to investigate the association between body mass index and postoperative outcomes after laparoscopic major hepatectomies.

METHODS

This is a retrospective review of 4,348 laparoscopic major hepatectomies at 58 centers between 2005 and 2021, of which 3,383 met the study inclusion criteria. Concomitant major operations, vascular resections, and previous liver resections were excluded. Associations between body mass index and perioperative outcomes were analyzed using restricted cubic splines. Modeled effect sizes were visually rendered and summarized.

RESULTS

A total of 1,810 patients (53.5%) had normal weight, whereas 1,057 (31.2%) were overweight and 392 (11.6%) were obese. One hundred and twenty-four patients (3.6%) were underweight. Most perioperative outcomes showed a linear worsening trend with increasing body mass index. There was a statistically significant increase in open conversion rate (16.3%, 10.8%, 9.2%, and 5.6%, P < .001), longer operation time (320 vs 305 vs 300 and 266 minutes, P < .001), increasing blood loss (300 vs 300 vs 295 vs 250 mL, P = .022), and higher postoperative morbidity (33.4% vs 26.3% vs 25.0% vs 25.0%, P = .009) in obese, overweight, normal weight, and underweight patients, respectively (P < .001). However, postoperative major morbidity demonstrated a "U"-shaped association with body mass index, whereby the highest major morbidity rates were observed in underweight and obese patients.

CONCLUSION

Laparoscopic major hepatectomy was associated with poorer outcomes with increasing body mass index for most perioperative outcome measures.

Impact of body mass index on the difficulty and outcomes of laparoscopic left lateral sectionectomy

INTRODUCTION

Currently, the impact of body mass index (BMI) on the outcomes of laparoscopic liver resections (LLR) is poorly defined. This study attempts to evaluate the impact of BMI on the peri-operative outcomes following laparoscopic left lateral sectionectomy (L-LLS).

METHODS

A retrospective analysis of 2183 patients who underwent pure L-LLS at 59 international centers between 2004 and 2021 was performed. Associations between BMI and selected peri-operative outcomes were analyzed using restricted cubic splines.

RESULTS

A BMI of >27kg/m2 was associated with increased in blood loss (Mean difference (MD) 21 mls, 95% CI 5-36), open conversions (Relative risk (RR) 1.13, 95% CI 1.03-1.25), operative time (MD 11 min, 95% CI 6-16), use of Pringles maneuver (RR 1.15, 95% CI 1.06-1.26) and reductions in length of stay (MD -0.2 days, 95% CI -0.3 to -0.1). The magnitude of these differences increased with each unit increase in BMI. However, there was a "U" shaped association between BMI and morbidity with the highest complication rates observed in underweight and obese patients.

CONCLUSION

Increasing BMI resulted in increasing difficulty of L-LLS. Consideration should be given to its incorporation in future difficulty scoring systems in laparoscopic liver resections.

Impact of neoadjuvant chemotherapy on the difficulty and outcomes of laparoscopic and robotic major liver resections for colorectal liver metastases: A propensity-score and coarsened exact-matched controlled study

BACKGROUND

Minimal invasive liver resections are a safe alternative to open surgery. Different scoring systems considering different risks factors have been developed to predict the risks associated with these procedures, especially challenging major liver resections (MLR). However, the impact of neoadjuvant chemotherapy (NAT) on the difficulty of minimally invasive MLRs remains poorly investigated.

METHODS

Patients who underwent laparoscopic and robotic MLRs for colorectal liver metastases (CRLM) performed across 57 centers between January 2005 to December 2021 were included in this analysis. Patients who did or did not receive NAT were matched based on 1:1 coarsened exact and 1:2 propensity-score matching. Pre- and post-matching comparisons were performed.

RESULTS

In total, the data of 5189 patients were reviewed. Of these, 1411 procedures were performed for CRLM, and 1061 cases met the inclusion criteria. After excluding 27 cases with missing data on NAT, 1034 patients (NAT: n = 641; non-NAT: n = 393) were included. Before matching, baseline characteristics were vastly different. Before matching, the morbidity rate was significantly higher in the NAT-group (33.2% vs. 27.2%, p-value = 0.043). No significant differences were seen in perioperative outcomes after the coarsened exact matching. After the propensity-score matching, statistically significant higher blood loss (mean, 300 (SD 128-596) vs. 250 (SD 100-400) ml, p-value = 0.047) but shorter hospital stay (mean, 6 [4-8] vs. 6 [5-9] days, p-value = 0.043) were found in the NAT-group.

CONCLUSION

The current study demonstrated that NAT had minimal impact on the difficulty and outcomes of minimally-invasive MLR for CRLM.

Robotic versus laparoscopic liver resections for hepatolithiasis: an international multicenter propensity score matched analysis

INTRODUCTION

Minimally invasive liver resection (MILR) is widely recognized as a safe and beneficial procedure in the treatment of both malignant and benign liver diseases. Hepatolithiasis has traditionally been reported to be endemic only in East Asia, but has seen a worldwide uptrend in recent decades with increasingly frequent and invasive endoscopic instrumentation of the biliary tract for a myriad of conditions. To date, there has been a woeful lack of high-quality evidence comparing the laparoscopic (LLR) and robotic (RLR) approaches to treatment hepatolithiasis.

METHODS

This is an international multicenter retrospective analysis of 273 patients who underwent RLR or LRR for hepatolithiasis at 33 centers in 2003-2020. The baseline clinicopathological characteristics and perioperative outcomes of these patients were assessed. To minimize selection bias, 1:1 (48 and 48 cases of RLR and LLR, respectively) and 1:2 (37 and 74 cases of RLR and LLR, respectively) propensity score matching (PSM) was performed.

RESULTS

In the unmatched cohort, 63 (23.1%) patients underwent RLR, and 210 (76.9%) patients underwent LLR. Patient clinicopathological characteristics were comparable between the groups after PSM. After 1:1 and 1:2 PSM, RLR was associated with less blood loss (p = 0.003 in 1:2 PSM; p = 0.005 in 1:1 PSM), less patients with blood loss greater than 300 ml (p = 0.024 in 1:2 PSM; p = 0.027 in 1:1 PSM), and lower conversion rate to open surgery (p = 0.003 in 1:2 PSM; p < 0.001 in 1:1 PSM). There was no significant difference between RLR and LLR in use of the Pringle maneuver, median Pringle maneuver duration, 30-day readmission rate, postoperative morbidity, major morbidity, reoperation, and mortality.

CONCLUSION

Both RLR and LLR were safe and feasible for hepatolithiasis. RLR was associated with significantly less blood loss and lower open conversion rate.

Propensity score-matched analysis of laparoscopic-assisted and hand-assisted laparoscopic liver resection versus pure laparoscopic liver resection: an international multicenter study

BACKGROUND

Laparoscopic-assisted (LALR) and hand-assisted (HALR) liver resections have been utilized during the early adoption phase by surgeons when transitioning from open surgery to pure LLR. To date, there are limited data reporting on the outcomes of LALR or HALR compared to LLR. The objective was to compare the perioperative outcomes after LALR and HALR versus pure LLR.

METHODS

This is an international multicentric analysis of 6609 patients undergoing minimal-invasive liver resection at 21 centers between 2004 and 2019. Perioperative outcomes were analyzed after propensity score matching (PSM) comparison between LALR and HALR versus LLR.

RESULTS

5279 cases met study criteria of whom 5033 underwent LLR (95.3%), 146 underwent LALR (2.8%) and 100 underwent HALR (1.9%). After 1:4 PSM, LALR was associated with inferior outcomes as evidenced by the longer postoperative stay, higher readmission rate, higher major morbidity rate and higher in-hospital mortality rate. Similarly, 1:6 PSM comparison between HALR and LLR also demonstrated poorer outcomes associated with HALR as demonstrated by the higher open conversion rate and higher blood transfusion rate. All 3 approaches technical variants demonstrated the same oncological radicality (R1 rate).

CONCLUSION

LALR and HALR performed during the learning curve was associated with inferior perioperative outcomes compared to pure LLR.

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.

Laparoscopic versus open resection of hepatocellular carcinoma in patients with cirrhosis

Hepatocellular carcinoma (HCC) is the sixth commonest malignancy worldwide, and the fourth-leading cause of cancer related death. Partial liver resection (LR) forms the mainstay of therapy for suitable patients with preserved liver function. In recent years, significant advances in surgical technology, refinement of operative techniques and improvements in peri-operative care have facilitated the widespread adoption of laparoscopic liver resection (LLR) with encouraging outcomes. Liver cirrhosis (LC) is present in up to 80% of patients with HCC, and adds a further dimension of complexity to LR. Cirrhotic patients have a propensity for greater intraoperative blood loss as well as increased postoperative complications such as refractory ascites and posthepatectomy liver failure. Tumor localization within the fibrotic parenchyma is challenging, giving rise to concerns about resection margin status. Patients are also at higher risk of developing metachronous lesions, which affects long-term survival. Presently, the exact role of LLR in HCC patients with underlying LC is not well-defined. Current evidence suggests that LLR offers a multitude of benefits in the short-term such as reduced blood loss and blood transfusion requirements and lower morbidity, when compared to open resection. Oncologic adequacy and long-term survival do not appear to be compromised. Special consideration must be given for LLR in patients with advanced cirrhosis, or those who require extensive major hepatectomies. We present here a brief review of the literature surrounding LLR for HCC on a background of LC.

Association of standardized liver volume and body mass index with outcomes of minimally invasive liver resections

INTRODUCTION

While minimally invasive liver resections (MILR) have demonstrated advantages in improved post-operative recovery, widespread adoption is hampered by inherent technical difficulties. Our study attempts to analyze the role of anthropometric measures in MILR-related outcomes.

METHODS

Between 2012 and 2020, 676 consecutive patients underwent MILR at the Singapore General Hospital of which 565 met study criteria and were included. Patients were stratified based on Body Mass Index (BMI) as well as Standardized Liver Volumes (SLV). Associations between BMI and SLV to selected peri-operative outcomes were analyzed using restricted cubic splines.

RESULTS

A BMI of ≥ 29 was associated with increase in blood loss [Mean difference (MD) 69 mls, 95% CI 2 to 137] as well as operative conversions [Relative Risk (RR) 1.63, 95% CI 1.02 to 2.62] among patients undergoing MILR while a SLV of 1600 cc or higher was associated with an increase in blood loss (MD 30 mls, 95% CI 10 to 49). In addition, a BMI of ≤ 20 was associated with an increased risk of major complications (RR 2.25, 95% 1.16 to 4.35). The magnitude of differences observed in these findings increased with each unit change in BMI and SLV.

CONCLUSION

Both BMI and SLV were useful anthropometric measures in predicting peri-operative outcomes in MILR and may be considered for incorporation in future difficulty scoring systems for MILR.

Utility of the Iwate difficulty scoring system for laparoscopic right posterior sectionectomy: do surgical outcomes differ for tumors in segments VI and VII?

INTRODUCTION

The Iwate Score (IS) have not been well-validated for specific procedures, especially for right posterior sectionectomy (RPS). In this study, the utility of the IS was determined for laparoscopic (L)RPS and the effect of tumor location on surgical outcomes was investigated.

METHODS

Post-hoc analysis of 647 L-RPS performed in 40 international centers of which 596L-RPS cases met the inclusion criteria. Baseline characteristics and perioperative outcomes of patients stratified based on the Iwate score were compared to determine whether a correlation with surgical difficulty existed. A 1:1 Mahalanobis distance matching was utilized to investigate the effect of tumor location on L-RPS outcomes.

RESULTS

The patients were stratified into 3 levels of difficulty (31 intermediate, 143 advanced, and 422 expert) based on the IS. When using a stepwise increase of the IS excluding the tumor location score, only Pringle's maneuver was more frequently used in the higher surgical difficulty level (35.5%, 54.6%, and 65.2%, intermediate, advanced, and expert levels, respectively, Z = 3.34, p = 0.001). Other perioperative results were not associated with a statistical gradation toward higher difficulty level. 80 of 85 patients with a segment VI lesion and 511 patients with a segment VII lesion were matched 1:1. There were no significant differences in the perioperative outcomes of the two groups including open conversion, operating time, blood loss, intraoperative blood transfusion, postoperative stay, major morbidity, and mortality.

CONCLUSION

Among patients undergoing L-RPS, the IS did not significantly correlate with most outcome measures associated with intraoperative difficulty and postoperative outcomes. Similarly, tumor location had no effect on L-RPS outcomes.

Robotic Versus Laparoscopic Left and Extended Left Hepatectomy: An International Multicenter Study Propensity Score-Matched Analysis

BACKGROUND

Controversies exist among liver surgeons regarding clinical outcomes of the laparoscopic versus the robotic approach for major complex hepatectomies. The authors therefore designed a study to examine and compare the perioperative outcomes of laparoscopic left hepatectomy or extended left hepatectomy (L-LH/L-ELH) versus robotic left hepatectomy or extended left hepatectomy (R-LH/R-ELH) using a large international multicenter collaborative database.

METHODS

An international multicenter retrospective analysis of 580 patients undergoing L-LH/L-ELH or R-LH/R-ELH at 25 specialized hepatobiliary centers worldwide was undertaken. Propensity score-matching (PSM) was used at a 1:1 nearest-neighbor ratio according to 15 perioperative variables, including demographics, tumor characteristics, Child-Pugh score, presence of portal hypertension, multiple resections, histologic diagnosis, and Iwate difficulty grade.

RESULTS

Before the PSM, 190 (32 %) patients underwent R-LH/R-ELH, and 390 (68 %) patients underwent L-LH/L-ELH. After the matching, 164 patients were identified in each arm without significant differences in demographics, preoperative variables, medical history, tumor pathology, tumor characteristics, or Iwate score. Regarding intra- and postoperative outcomes, the rebotic approach had significantly less estimated blood loss (EBL) (100 ml [IQR 200 ml] vs 200 ml [IQR 235 ml]; p = 0.029), fewer conversions to open operations (n = 4 [2.4 %] vs n = 13, [7.9 %]; p = 0.043), and a shorter hospital stay (6 days [IQR 3 days] vs 7 days [IQR 3.3 days]; p = 0.009).

CONCLUSION

Both techniques are safe and feasible in major hepatic resections. Compared with L-LH/L-ELH, R-LH/R-ELH is associated with less EBL, fewer conversions to open operations, and a shorter hospital stay.

Poor utility of current nomograms assessing the risk of intraoperative blood transfusion in patients undergoing liver resection for hepatocellular carcinoma and proposal of a new model

BACKGROUND

The Memorial Sloan Kettering Cancer Center nomogram, the predictive scoring system of Yamamoto et al, and the 3-point transfusion risk score of Lemke et al are models used to determine the probability of receiving intraoperative blood transfusion in patients undergoing liver resection. However, the external validity of these models remains unknown. The objective of this study was to evaluate their predictive performance in an external cohort of patients with hepatocellular carcinoma. We also aimed to identify predictors of blood transfusion and develop a new predictive model for blood transfusion.

METHODS

Post hoc analysis of our prospective database of 1,081 patients undergoing liver resection for hepatocellular carcinoma from 2001 to 2018. The predictive performance of current prediction models was evaluated using C statistics. Demographic and clinical variables as predictors of blood transfusion were assessed. Using logistic regression, an alternative model was created.

RESULTS

The Lemke transfusion risk score performed better than the Memorial Sloan Kettering Cancer Center nomogram (0.69, 95% confidence interval 0.66-0.73 vs 0.66, 95% liver resection 0.62-0.69) (P < .001). The model from Yamamoto et al performed comparably with no statistically significant differences found through pairwise comparison. In our alternative model, hemoglobin level, albumin level, liver resection type, and tumor size were independent predictors of blood transfusion. The new HATS model obtained a C statistic of 0.74 (95% confidence interval 0.71-0.78), performing significantly better than the previous 3 models (P ≤ 0.001 for all).

CONCLUSION

The existing Memorial Sloan Kettering Cancer Center, Yamamoto et al, and Lemke et al had nomograms with the suboptimal accuracy of predicting risk of intraoperative blood transfusion in patients undergoing liver resection for hepatocellular carcinoma. The proposed HATS model was more accurate at predicting patients at risk of blood transfusion.

Minimally-invasive versus open pancreatoduodenectomies with vascular resection: A 1:1 propensity-matched comparison study

Background:

Minimally invasive pancreatic pancreatoduodenectomy (MIPD) is increasingly adopted worldwide and its potential advantages include reduced hospital stay and decrease pain. However, evidence supporting the role of MIPD for tumours requiring vascular reconstruction remains limited and requires further evaluation. This study aims to investigate the safety and efficacy of MIPD with vascular resection (MIPDV) by performing a 1:1 propensity-score matched (PSM) comparison with open pancreatoduodenectomy with vascular resection (OPDV) based on a single surgeon's experience.

Methods:

This is a retrospective review of 41 patients who underwent PDV between 2011 and 2020 by a single surgeon. After PSM, the comparison was made between 13 MIPDV and 13 OPDV.

Results:

Thirty-six patients underwent venous reconstruction (VR) only and 5 underwent arterial reconstruction of which 4 had concomitant VR. The types of VR included 22 wedge resections with primary repair, 8 segmental resections with primary anastomosis and 11 requiring interposition grafts. Post-operative pancreatic fistula (POPF) occurred in 3 (7.3%) patients. Major complications (>Grade 2) occurred in 16 (39%) patients, of which 7 were due to delayed gastric emptying requiring nasojejunal tube placement. There was 1 (2.4%) 30-day mortality (OPDV). Of the 13 MIPDV, there were 3 (23.1%) open conversions. PSM comparison demonstrated that MIPDV was associated with longer median operative time (720 min vs. 485 min (P = 0.018). There was no statistically significant difference in other key perioperative outcomes such as intra-operative blood loss, overall morbidity, major morbidity rate, POPF and length of stay.

Conclusion:

Our initial experience with the adoption MIPDV has demonstrated it to be safe with comparable outcomes to OPDV despite the longer operation time.

Effect of age on the short- and long-term outcomes of patients undergoing curative liver resection for HCC

BACKGROUND

Few studies have evaluated the outcomes of curative liver resection (LR) in octogenarian patients, analysed cancer-specific survival (CSS) with HCC-related death or explored the age-varying effect of HCC-related death in elderly patients undergoing LR. We aim to determine the effect of age on the short and long-term outcomes of LR for HCC.

METHODOLOGY

Between 2000 and 2018, 1,092 patients with primary HCC who underwent LR with curative intent were retrospectively reviewed. The log-rank test and Gray's test were used to assess the equality of survivor functions and competing risk-adjusted cumulative incidence functions between patients in the three age categories respectively. Regression adjustment was used to control for confounding bias via a Principal Component Analysis. Quantile, Firth logistic, Cox, and Fine-Gray competing risk regression were used to analyse continuous, binary, time-to-event, and cause-specific survival respectively. Restricted cubic splines were used to illustrate the dose-effect relationship between age and patient outcomes.

RESULTS

The study comprised of 764 young patients (<70 years), 278 septuagenarians (70-79 years old) and 50 octogenarians (≥80 years). Compared to young patients, octogenarians had significantly lower 5-year OS(62.1% vs 37.7%, p < 0.001). However, there was no significant difference in 1-year RFS(73.1% vs 67.0%, p = 0.774) or 5-year CSS (5.4% vs 15.2%, p = 0.674). Every 10-year increase in age was significantly associated with an increase length of stay (p < 0.001), postoperative complications (p = 0.004) and poorer OS(p = 0.018) but not significantly associated with major complications (p = 0.279), CSS(p = 0.338) or RFS(p = 0.941).

CONCLUSION

Age by itself was associated with OS after LR for HCC but was not a significant risk factor for HCC-related death.

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.

Propensity-Score Matched Analyses Comparing Clinical Outcomes of Minimally Invasive Versus Open Distal Pancreatectomies: A Single-Center Experience

BACKGROUND

Minimally invasive distal pancreatectomy (MIDP) is being adopted increasingly worldwide. This study aimed to compare the short-term outcomes of patients who underwent MIDP versus open distal pancreatectomy (ODP).

METHODS

A retrospective review of all patients who underwent a DP in our institution between 2005 and 2019 was performed. Propensity score matching based on relevant baseline factors was used to match patients in the ODP and MIDP groups in a 1:1 manner. Outcomes reported include operative duration, blood loss, postoperative length of stay, morbidity, mortality, postoperative pancreatic fistula rates, reoperation and readmission.

RESULTS

In total, 444 patients were included in this study. Of 122 MIDP patients, 112 (91.8%) could be matched. After matching, the median operating time for MIDP was significantly longer than ODP [260 min (200-346.3) vs 180 (135-232.5), p < 0.001], while postoperative stay for MIDP was significantly shorter [median 6 days (5-8) versus 7 days (6-9), p = 0.015]. There were no significant differences noted in any of the other outcomes measured. Over time, we observed a decrease in the operation times of MIDP performed at our institution.

CONCLUSION

Adoption of MIDP offers advantages over ODP in terms of a shorter postoperative hospital stay, without an increase in morbidity and/or mortality but at the expense of a longer operation time.

Outcomes of laparoscopic, robotic, and open pancreatoduodenectomy: A network meta-analysis of randomized controlled trials and propensity-score matched studies

BACKGROUND

This network meta-analysis was performed to determine the optimal surgical approach for pancreatoduodenectomy by comparing outcomes after laparoscopic pancreatoduodenectomy, robotic pancreatoduodenectomy and open pancreatoduodenectomy.

METHODS

A systematic search of the PubMed, EMBASE, Scopus, and Web of Science databases was conducted to identify eligible randomized controlled trials and propensity-score matched studies.

RESULTS

Four randomized controlled trials and 23 propensity-score matched studies comprising a total of 4,945 patients were included for analysis. Operation time for open pancreatoduodenectomy was shorter than both laparoscopic pancreatoduodenectomy (mean difference -57.35, 95% CI 26.25-88.46 minutes) and robotic pancreatoduodenectomy (mean difference -91.08, 95% CI 48.61-133.56 minutes), blood loss for robotic pancreatoduodenectomy was significantly less than both laparoscopic pancreatoduodenectomy (mean difference -112.58, 95% CI 36.95-118.20 mL) and open pancreatoduodenectomy (mean difference -209.87, 95% CI 140.39-279.36 mL), both robotic pancreatoduodenectomy and laparoscopic pancreatoduodenectomy were associated with reduced rates of delayed gastric emptying compared with open pancreatoduodenectomy (odds ratio 0.59, 95% CI 0.39-0.90 and odds ratio 0.69, 95% CI 0.50-0.95, respectively), robotic pancreatoduodenectomy was associated with fewer wound infections compared with open pancreatoduodenectomy (odds ratio 0.35, 95% CI 0.18-0.71), and laparoscopic pancreatoduodenectomy patients enjoyed significantly shorter length of stay compared with open pancreatoduodenectomy (odds ratio 0.43, 95% CI 0.28-0.95). There were no differences in other outcomes.

CONCLUSION

This network meta-analysis of high-quality studies suggests that when laparoscopic pancreatoduodenectomy and robotic pancreatoduodenectomy are performed in high-volume centers, short-term perioperative and oncologic outcomes are largely comparable, if not slightly improved, compared with traditional open pancreatoduodenectomy. These findings should be corroborated in further prospective randomized studies.

Impact of introduction of an enhanced recovery protocol on the outcomes of laparoscopic liver resections: A propensity-score matched study

BACKGROUND

Presently, data on the impact of enhanced recovery protocols on the outcomes of laparoscopic liver resection remain limited. We performed propensity matched analysis comparing the outcomes between patients undergoing laparoscopic liver resection before and after the introduction of an enhanced recovery protocol.

METHODS

Between 2013 and 2019, 462 consecutive patients underwent laparoscopic liver resection by 3 surgeons of which 360 met the study inclusion criteria. There were 89 patients who underwent surgery under an enhanced recovery protocol and 271 without an enhanced recovery protocol. One-to-one propensity matched analysis was performed for 84 enhanced recovery protocol patients and 84 nonenhanced recovery protocol patients.

RESULTS

Comparisons between propensity matched cohorts revealed that patients who received laparoscopic liver resection with enhanced recovery protocol had reduced median blood loss (200 vs 300 mL, P = .013), postoperative stay (3 vs 4 days, P = .003), and lower open conversion rates (0% vs 8.3%, P = .008). There was no difference in other key perioperative outcomes such as operation time, postoperative morbidity, postoperative major morbidity, and 30-day readmission rates.

CONCLUSION

A combined approach of enhanced recovery protocol and laparoscopic liver resection was associated with improved perioperative outcomes as opposed to laparoscopic liver resection alone.

Impact of tumor size on the difficulty of minimally invasive liver resection

INTRODUCTION

We performed this study in order to investigate the impact of tumour size on the difficulty of MILR, as well as to elucidate the optimal tumour size cut-off/s to distinguish between 'easy' and 'difficult' MILRs.

MATERIALS AND METHODS

This is retrospective review of 603 consecutive patients who underwent MILR between 2006 and 2019 of which 461 met the study inclusion criteria. We first conducted an exploratory analysis to visualize the associations between tumor size and various surrogates of laparoscopic difficulty in order to determine to optimal tumor size cutoff for stratification. Visual inspection of flexible spline-based models as well as quantitative evidence determined that perioperative outcomes differed between patients with tumor size of 30-69 mm and tumours ≥70 mm. These cutoffs were used for further downstream analyses.

RESULTS

The cohort of 461 patients was divided into 3 groups based on tumour diameter size. Patients with larger tumours experienced longer operating times ((P_{Group 2 vs 1}<0.001, P_{Group 3 vs 1}<0.001, P_{Group 3 vs 2}<0.001), higher blood loss (P_{Group 2 vs 1}<0.001, P_{Group 3 vs 1}<0.001, P_{Group 3 vs 2}<0.001), as well as significantly longer hospital stay (P_{Group 2 vs 1}<0.001, P_{Group 3 vs 1}<0.001, P_{Group 3 vs 2}<0.001). There was a monotonic trend towards increasing blood transfusion rates (P = 0.006), overall morbidity (P = 0.029) and 90-day mortality rates (P = 0.047) with increasing tumour size.

CONCLUSION

Although tumour size of 30 mm serves as an optimal cut-off for predicting difficult resections as per the Iwate criteria, a trichotomy (<30 mm, 30-69 mm, ≥70 mm) may provide additional granularity. Further large-scale prospective studies are needed to corroborate these findings.

Learning curves in minimally invasive hepatectomy: systematic review and meta-regression analysis

BACKGROUND

Minimally invasive hepatectomy (MIH) has become an important option for the treatment of various liver tumours. A major concern is the learning curve required. The aim of this study was to perform a systematic review and summarize current literature analysing the learning curve for MIH.

METHODS

A systematic review of the literature pertaining to learning curves in MIH to July 2019 was performed using PubMed and Scopus databases. All original full-text articles published in English relating to learning curves for both laparoscopic liver resection (LLR), robotic liver resection (RLR), or a combination of these, were included. To explore quantitatively the learning curve for MIH, a meta-regression analysis was performed.

RESULTS

Forty studies relating to learning curves in MIH were included. The median overall number of procedures required in studies utilizing cumulative summative (CUSUM) methodology for LLR was 50 (range 25-58) and for RLR was 25 (16-50). After adjustment for year of adoption of MIH, the CUSUM-derived caseload to surmount the learning curve for RLR was 47.1 (95 per cent c.i. 1.2 to 71.6) per cent; P = 0.046) less than that required for LLR. A year-on-year reduction in the number of procedures needed for MIH was observed, commencing at 48.3 cases in 1995 and decreasing to 23.8 cases in 2015.

CONCLUSION

The overall learning curve for MIH decreased steadily over time, and appeared less steep for RLR compared with LLR.

Continuous improvements in short and long-term outcomes after partial hepatectomy for hepatocellular carcinoma in the 21st century: Single institution experience with 1300 resections over 18 years

INTRODUCTION

To investigate the changing trends in short- and long-term outcomes after partial hepatectomy(PH) for hepatocellular carcinoma(HCC) performed in the 21st century.

METHODS

A retrospective review was conducted on 1300 consecutive patients who underwent PH for HCC. The study cohort was divided into 3 time periods(P): P1(2000-2005), P2(2006-2011) and P3(20012-2017).

RESULTS

Comparison between the patients' baseline demographic features across the 3 periods demonstrated that patients were significantly older, had decreasing frequency of hepatitis B, increasing non-alcoholic fatty liver disease, lower alpha-feto protein(AFP) level, lower creatinine levels, less likely to undergo emergency surgery, less likely to undergo major hepatectomy, more likely to undergo repeat resection and minimally-invasive surgery. There was also an increase in operation time, decrease in blood loss, increase frequency in the use of Pringles manoeuvre, decrease liver failure, decrease length of stay and decrease postoperative mortality. HCC resected were of smaller size, less likely to demonstrate microvascular invasion and less likely to have close margins. This was associated with significant improvement in overall survival and recurrence free interval over time. Period of resection was an independent predictor of 90-day mortality and OS on multivariate analysis.

CONCLUSION

We observed a continuous improvement in postoperative outcomes including postoperative mortality and long-term survival after PH for HCC over the past 18 years.

Comparative outcomes of needlescopic, single-incision laparoscopic, standard laparoscopic, mini-laparotomy, and open cholecystectomy: A systematic review and network meta-analysis of 96 randomized controlled trials with 11,083 patients

BACKGROUND

Most randomized trials on minimally invasive cholecystectomy have been conducted with standard (3/4-port) laparoscopic or open cholecystectomy serving as the control group. However, there exists a dearth of head-to-head trials that directly compare different minimally invasive techniques for cholecystectomy (eg, single-incision laparoscopic cholecystectomy versus needlescopic cholecystectomy). Hence, it remains largely unknown how the different minimally invasive cholecystectomy techniques fare up against one another.

METHODS

To minimize selection and confounding biases, only randomized controlled trials were considered for inclusion. Perioperative outcomes were compared using frequentist network meta-analyses. The interpretation of the results was driven by treatment effects and surface under the cumulative ranking curve values. A sensitivity analysis was also undertaken focusing on a subgroup of randomized controlled trials, which recruited patients with only uncomplicated cholecystitis.

RESULTS

Ninety-six eligible randomized controlled trials comprising 11,083 patients were identified. Risk of intra-abdominal infection or abscess, bile duct injury, bile leak, and open conversion did not differ significantly between minimally invasive techniques. Needlescopic cholecystectomy was associated with the lowest rates of wound infection (surface under the cumulative ranking curve value = 0.977) with an odds ratio of 0.095 (95% confidence interval: 0.023-0.39), 0.32 (95% confidence interval: 0.11-0.98), 0.33 (95% confidence interval: 0.11-0.99), 0.36 (95% confidence interval: 0.14-0.98) compared to open cholecystectomy, single-incision laparoscopic cholecystectomy, mini-laparotomy, and standard laparoscopic cholecystectomy, respectively. Mini-laparotomy was associated with the shortest operative time (surface under the cumulative ranking curve value = 0.981) by a mean difference of 22.20 (95% confidence interval: 13.79-30.62), 12.17 (95% confidence interval: 1.80-22.54), 9.07 (95% confidence interval: 1.59-16.54), and 8.36 (95% confidence interval: -1.79 to 18.52) minutes when compared to single-incision laparoscopic cholecystectomy, needlescopic cholecystectomy, standard laparoscopic cholecystectomy, and open cholecystectomy, respectively. Needlescopic cholecystectomy appeared to be associated with the shortest hospitalization (surface under the cumulative ranking curve value = 0.717) and lowest postoperative pain (surface under the cumulative ranking curve value = 0.928).

CONCLUSION

Perioperative outcomes differed across minimally invasive techniques and, in some instances, afforded superior outcomes compared to standard laparoscopic cholecystectomy. These findings suggest that there may be equipoise for exploring further the utility of novel minimally invasive techniques and potentially incorporating them into the general surgery training curriculum.

Validation and comparison of the Iwate, IMM, Southampton and Hasegawa difficulty scoring systems for primary laparoscopic hepatectomies

BACKGROUND

Various difficulty scoring systems (DSS) have been formulated to grade the complexity of laparoscopic hepatectomies (LH). This study aims to externally validate and compare 4 contemporary DSS including the Iwate, Institut Mutualiste Montsouris (IMM), Southampton and Hasegawa DSS in predicting the intraoperative technical difficulty and postoperative outcomes after LH.

METHODS

Retrospective review of 548 consecutive patients who underwent LH of which 455 met the study inclusion criteria. Outcomes measures of technical difficulty included operation time, Pringles maneuver, blood loss and blood transfusion rate. Postoperative outcomes measured included morbidity, major morbidity and postoperative hospital stay.

RESULTS

There was a statistically significant progressive increase in blood loss, blood transfusion rate, operation time and postoperative stay associated with all 4 DSS. There was also good calibration with respect to blood loss, operation time, Pringles maneuver, open conversion rate, postoperative morbidity, postoperative major morbidity and postoperative stay for all 4 DSS. The Southampton score demonstrated the poorest calibration in terms of operation time and discrimination in terms of application of Pringles maneuver and major morbidity amongst all 4 systems.

CONCLUSION

All 4 DSS significantly correlated with outcome measures associated with intraoperative technical difficulty and postoperative outcomes. The Southampton DSS was the poorest system in our cohort of patients.

Laparoscopic liver resection for huge (≥10 cm) hepatocellular carcinoma: A coarsened exact-matched single-surgeon study

INTRODUCTION

Laparoscopic liver resection (LLR) is increasingly being utilised worldwide for the management of both benign and malignant liver tumours. However, there is limited data to date regarding the safety and feasibility of this approach for huge (≥10 cm) hepatocellular carcinomas (HCCs). We present here our early experience performing LLR for huge HCCs.

METHODS

We conducted a retrospective review of 280 consecutive patients who underwent LLR by a single surgeon from 2012 to August 2020.15 patients had a preoperative radiological diagnosis of huge (≥10 cm) HCC. Coarsened exact-matched (CEM) weighting was used to compare them to 101 patients who underwent LLR for non-huge HCC.

RESULTS

After CEM-weighting, both groups were well-balanced for baseline variables. There was no difference in the rates of open conversion. The huge HCC patients had a higher mean Iwate difficulty score than the non-huge HCC patients (9.13 vs 6.53, p = 0.007). As such, the median operating time for the huge HCC group was longer (360 min vs 240min, p = 0.049). However, there were no significant differences in estimated blood loss, proportion of patients requiring blood transfusion, utilization of Pringle maneuver or median Pringle duration. Post-operatively, there were no significant differences in median LOS, overall and major morbidity rates, and 90-day mortality rates between both groups. Median resection margins were also similar for both cohorts.

CONCLUSION

LLR may be performed successfully for selected patients with huge HCC, with encouraging perioperative outcomes and no compromise in oncologic efficacy.

Minimally invasive versus open right anterior sectionectomy and central hepatectomy for central liver malignancies: a propensity-score-matched analysis

BACKGROUND

The utility of minimally-invasive liver resection (MILR) for deep centrally located tumours (CLT) remains controversial. We aimed to review our institution's experience and outcomes with minimally invasive central hepatectomy (CH) and right anterior sectionectomy (RAS) for CLT in a propensity score-matched (PSM) analysis.

METHODS

Retrospective review of a prospectively maintained surgical database revealed 23 patients who underwent MILR (6 CH, 17 RAS) and 53 patients who underwent open liver resection (OLR; 24 CH, 29 RAS) for CLT. PSM in a 1:1 ratio identified two groups of patients with similar baseline clinicopathological characteristics. Peri-operative outcomes were then compared.

RESULTS

There was one laparoscopic-assisted, one robot-assisted and two laparoscopic-converted-open procedures in the MILR cohort. Across the unmatched cohort, there was only one mortality (MILR) and five patients with major morbidity (all OLR). MILR was associated with a longer operating time (P < 0.001), but shorter post-operative hospital stay (P = 0.002) and decreased morbidity (P = 0.018) in the unmatched cohort. Examination of peri-operative outcomes after PSM revealed that MILR was similarly associated with a longer operating time (P = 0.001) and shortened post-operative hospital stay (P = 0.043). OLR was associated with a significantly reduced application of Pringle manoeuvre (P = 0.004). There were no significant differences between MILR and OLR with regards to blood loss, blood transfusions, morbidity and margin status in the PSM analysis.

CONCLUSION

MILR for CLT is safe and feasible when performed by experienced surgeons. It is associated with shorter hospital stays but at the expense of longer operation times and more frequent application of Pringle manoeuver.

Robotic transduodenal ampullectomy: Case report and review of the literature

Ampullary neoplasms are relatively uncommon lesions with a risk of progression to malignancy. Depending on its nature, size and location, it may be best treated with endoscopic papillotomy, pancreaticoduodenectomy or transduodenal ampullectomy. Transduodenal ampullectomy offers a higher chance of complete resection compared to endoscopic papillotomy, and carries lower morbidity than a pancreaticoduodenectomy, making it the ideal choice for localised ampullary tumour not involving the ducts but not amenable to complete endoscopic resection. While traditionally performed via open surgery, it has been attempted via laparoscopic approach and more recently robotic approach. We present a case of a 63-year-old man who underwent a robotic transduodenal ampullectomy for ampullary adenoma with high grade dysplasia, and review the literature surrounding robotic transduodenal ampullectomy.

Impact of non-liver-related previous abdominal surgery on the difficulty of minimally invasive liver resections: a propensity score-matched controlled study

INTRODUCTION

The presence of previous abdominal surgery (PAS) has traditionally been considered to add difficulty to and increase risk of complications of laparoscopic procedures. This study aims to analyse the impact of non-liver-related PAS on the difficulty of minimally invasive liver resections (MILRs).

MATERIALS AND METHODS

After exclusion of patients with concomitant major surgical procedures as well as previous liver resections, 515 consecutive patients undergoing MILR in Singapore General Hospital from 2006 to 2019 were analysed, consisting of 161 MILR in patients with previous abdominal surgery (WPAS) and 354 MILR in patients without previous abdominal surgery (WOPAS). Propensity score-matched (PSM) comparison was performed between WPAS and WOPAS groups. In addition, subgroup analysis was made comparing previous upper or lower abdominal surgery and open versus minimally invasive approach of PAS. Outcomes measured include those associated with operative difficulty such as open conversion rates, operative time, blood loss, as well as morbidity and mortality rates.

RESULTS

MILR outcomes in patients WPAS are not inferior to those WOPAS. Overall open conversion rate was 8.2%, higher in patients WOPAS compared to patients WPAS (11.9% versus 3.5%, p = 0.015). Operating time (p = 0.942), blood loss (p = 0.063), intraoperative blood transfusion (p = 0.750), length of hospital stay (p = 0.206), morbidity (p = 0.217) and 30- and 90-day mortality (p = 1 & p = 0.367) were comparable between the two groups and subgroup analysis.

CONCLUSION

Outcomes of MILR in patients with previous non-liver-related abdominal surgery are not inferior to patients without previous abdominal surgery.

Learning curve of laparoscopic and robotic pancreas resections: a systematic review

BACKGROUND

Minimally invasive pancreatic resection has been shown recently in some randomized trials to be superior in selected perioperative outcomes compared with open resection when performed by experienced surgeons. However, minimally invasive pancreatic resection is associated with a long learning curve. This study aims to summarize the current evidence on the learning curve of minimally invasive pancreatic resection and define the number of cases required to surmount the learning curve.

METHODS

A systematic search was performed on PubMed, Embase, Scopus, and the Cochrane database using a detailed search strategy. Studies that did not describe the learning curve were excluded from the study. Data on the method of learning curve analysis, single surgeon versus institutional learning curve, and outcome measures were extracted and analyzed.

RESULTS

A total of 32 studies were included in the pooled analysis: 12 on laparoscopic pancreatoduodenectomy, 9 on robotic pancreatoduodenectomy, 12 on laparoscopic distal pancreatectomy, and 3 on robotic distal pancreatectomy. Sample population was comparable between laparoscopic pancreatoduodenectomy and robotic pancreatoduodenectomy (median 63 vs 65). Six of 12 studies and 7 of 9 studies used nonarbitrary methods of analysis in laparoscopic pancreatoduodenectomy and robotic pancreatoduodenectomy, respectively. Operating time was used as the single outcome measure in 4 of 12 studies in laparoscopic pancreatoduodenectomy and 5 of 9 studies in robotic pancreatoduodenectomy. Overall, there was no significant difference between the number of cases required to surmount the learning curve for laparoscopic pancreatoduodenectomy versus robotic pancreatoduodenectomy (laparoscopic pancreatoduodenectomy 34.1 [95% confidence interval 30.7-37.7] versus robotic pancreatoduodenectomy 36.7 [95% confidence interval 32.9-41.0]; P = .8241) and laparoscopic distal pancreatectomy versus robotic distal pancreatectomy (laparoscopic distal pancreatectomy 25.3 [95% confidence interval 22.5-28.3] versus robotic distal pancreatectomy 20.7 [95% confidence interval 15.8-26.5]; P = .5997.) CONCLUSION: This study provides a detailed summary of existing evidence around the learning curve in minimally invasive pancreatic resection. There was no significant difference between the learning curve for robotic pancreatoduodenectomy versus laparoscopic pancreatoduodenectomy and robotic distal pancreatectomy versus laparoscopic distal pancreatectomy. These findings were limited by the retrospective nature and heterogeneity of the studies published to date.

Use of Reinforced Staplers Decreases the Rate of Postoperative Pancreatic Fistula Compared to Bare Staplers After Minimally Invasive Distal Pancreatectomies

Background: Postoperative pancreatic fistula (POPF) is the most common and important cause of morbidity after distal pancreatectomy. Various transection and closure techniques of the pancreatic stump have been proposed with no robust evidence unanimously supporting one technique over the other. This study aims to compare the outcomes of minimally invasive distal pancreatectomy (MIDP) performed with reinforced stapler (RS) versus bare stapler (BS) with particular attention to the POPF. Methods: Retrospective review of 90 consecutive elective MIDP performed at a single institution between 2014 and 2019 was performed. The primary outcome was POPF as defined by the latest International Study Group of Pancreatic Fistula classification. MIDP with RS was adopted by two surgeons who subsequently performed all their consecutive surgeries with RS. Results: There were 25 and 65 patients who underwent MIDP with RS and BS, respectively. There were 8 (8.9%) open conversions and 17 (18.9%) patients experienced a POPF. Patients who underwent MIDP with RS had a significantly lower POPF rate (4% versus 24.6%, P = .025), lower major (>grade 2) morbidity rate (4% versus 21.5%, P = .046), and lower readmission rate (4% versus 27.7%, P = .014). On multivariate analysis, only the use of BS and obesity (body mass index ≥27.5) was independently associated with the development of a POPF. Conclusion: MIDP performed with RS was associated with a significantly lower rate of POPF, major morbidity, and readmissions compared to BS. The use of RS was protective against POPF.

Emergency laparoscopic surgery for ruptured pancreatic pseudocyst: Report of two cases and review of the literature

Pancreatic pseudocyst (PP) is a known complication of pancreatitis. When a rupture occurs, patients often become haemodynamically unstable and require emergency surgery for source control. Conventionally, such a procedure is carried out through open technique due to patient, surgeon and technical factors. We present two cases of emergency laparoscopic surgery performed for ruptured PP. Our first patient was a 53-year-old male with a ruptured 17.6 cm pancreatic body pseudocyst who underwent a laparoscopic washout, adhesiolysis, necrosectomy, distal pancreatectosplenectomy and cholecystectomy. The second patient was a 66-year-old male with a ruptured 11 cm pancreatic body pseudocyst who underwent laparoscopic surgery, subsequently converted to hand-assisted surgery. We compare our cases with the existing literature and discuss pertinent management considerations. In conclusion, we demonstrated that emergency laparoscopic adhesiolysis, necrosectomy and distal pancreatosplenectomy are feasible and safe for the management of ruptured pseudocyst when performed by an experienced surgeon. However, further studies are needed to determine the advantages or limitations of the minimally invasive surgical approach for the management of these complicated cases.

Outcome of minimally invasive liver resection for extrapancreatic biliary malignancies: A single-institutional experience

Background:

Minimally invasive liver resection (MILR) has been increasingly adopted over the past decade, and its application has been expanded to the management of extrapancreatic biliary malignancies (EPBMs). We aimed to evaluate the peri- and post-operative outcome of patients undergoing MILR for suspected EPMB.

Methods:

Forty-four consecutive patients who underwent MILR with a curative intent for EPBM at Singapore General Hospital between 2011 and 2018 were identified from a prospectively maintained surgical database. Clinical and operative data were analysed and compared to provide information and make comparisons on peri- and post-operative outcomes.

Results:

A total of 26, 5 and 13 patients underwent MILR for intrahepatic cholangiocarcinoma (ICC), perihilar cholangiocarcinoma (PHC) and gallbladder carcinoma (GBCA), respectively. Six major hepatectomies were performed, of which one was laparoscopic assisted and another was robot assisted. Ten patients underwent posterosuperior segmentectomies. There was one open conversion. The mean operative time was 266.5 min, and the mean blood loss was 379 ml. The mean length of hospital stay was 4.7 days with no incidences of 30- and 90-day mortality. The rate of recurrence-free survival (RFS) was 75% (at least 12-month follow-up). There was a significantly higher rate of robot-assisted procedures in patients undergoing MILR for GBCA/PHC as compared to ICC (P = 0.034). Patients undergoing posterosuperior segmentectomies required longer operative time (P = 0.018) with an increased need for (P = 0.001) and duration of (P = 0.025) Pringles manoeuvre. There were no differences in operative time, blood loss, morbidity, mortality or RFS between the above groups.

Conclusion:

Minimally invasive surgery can be adopted safely with a low open conversion rate for EPBMs.

Changing trends in the clinicopathological features, practices and outcomes in the surgical management for cystic lesions of the pancreas and impact of the international guidelines: Single institution experience with 462 cases between 1995-2018

INTRODUCTION

The impact on clinical practice of the international guidelines including the Sendai Guidelines (SG06) and Fukuoka Guidelines (FG12) on the management of cystic lesions of the pancreas (CLP) has not been well-studied. The primary aim was to examine the changing trends and outcomes in the surgical management of CLP in our institution over time and to determine the impact of these guidelines on our institution practice.

METHODS

462 patients with surgically-treated CLP were retrospectively reviewed and classified under the 2 guidelines. The cohort was divided into 3 time periods: 1998-2006, 2007-2012 and 2013 to 2018.

RESULTS

Comparison across the 3 time periods demonstrated significantly increasing frequency of older patients, asymptomatic CLP, male gender, smaller tumor size, elevated Ca 19-9, use of magnetic resonance imaging (MRI) and use of endoscopic ultrasound (EUS) prior to surgery. There was also significantly increasing frequency of adherence to the international guidelines as evidenced by the increasing proportion of HR^SG06 and HR^FG12 CLP with a corresponding lower proportion of LR^SG06 and LR^FG12 being resected. This resulted in a significantly higher proportion of resected CLP whereby the final pathology confirmed that a surgery was actually indicated.

CONCLUSIONS

Over time, there was increasing adherence to the international guidelines for the selection of patients for surgical resection as evidenced by the significantly increasing proportion of HR^SG06 and HR^FG06 CLPs undergoing surgery. This was associated with a significantly higher proportion of patients with a definitive indication for surgery. These suggested that over time, there was a continuous improvement in our selection of appropriate CLP for surgical treatment.

Adoption of Robotic Liver, Pancreatic and Biliary Surgery in Singapore: A Single Institution Experience with Its First 100 Consecutive Cases

Introduction: Presently, robotic hepatopancreatobiliary surgery (RHPBS) is increasingly adopted worldwide. This study reports our experience with the first 100 consecutive cases of RHPBS in Singapore. Methods: Retrospective review of a single-institution prospective database of the first 100 consecutive RHPBS performed over 6 years from February 2013 to February 2019. Eighty-six cases were performed by a single surgeon. Results: The 100 consecutive cases included 24 isolated liver resections, 48 pancreatic surgeries (including 2 bile duct resections) and 28 biliary surgeries (including 8 with concomitant liver resections). They included 10 major hepatectomies, 15 pancreaticoduodenectomies, 6 radical resections for gallbladder carcinoma and 8 hepaticojejunostomies. The median operation time was 383 minutes, with interquartile range (IQR) of 258 minutes and there were 2 open conversions. The median blood loss was 200ml (IQR 350ml) and 15 patients required intra-operative blood transfusion. There were no post-operative 90-day nor in-hospital mortalities but 5 patients experienced major (> grade 3a) morbidities. The median post-operative stay was 6 days (IQR 5 days) and there were 12 post-operative 30-day readmissions. Comparison between the first 50 and the subsequent 50 patients demonstrated a significant reduction in blood loss, significantly lower proportion of malignant indications, and a decreasing frequency in liver resections performed. Conclusion: Our experience with the first 100 consecutive cases of RHPBS confirms its feasibility and safety when performed by experienced laparoscopic hepatopancreatobiliary surgeons. It can be performed for even highly complicated major hepatopancreatobiliary surgery with a low open conversion rate. Keywords: Biliary surgery, hepaticojejunostomy, liver resection, pancreas, pancreaticoduodenectomy

Comparison between long and short-term venous patencies after pancreatoduodenectomy or total pancreatectomy with portal/superior mesenteric vein resection stratified by reconstruction type

Background

Venous reconstruction has been recently demonstrated to be safe for tumours with invasion into portal vein and/or superior mesenteric vein. This study aims to compare the patency between various venous reconstructions.

Methods

This is retrospective study of 76 patients who underwent pancreaticoduodenectomy or total pancreatectomy with venous reconstruction from 2006 to 2018. Patient demographics, tumour histopathology, morbidity, mortality and patency were studied. Kaplan-Meier estimates were performed for primary venous patency.

Results

Sixty-two patients underwent pancreaticoduodenectomy and 14 underwent total pancreatectomy. Forty-seven, 19 and 10 patients underwent primary repair, end-to-end anastomosis and interposition graft respectively. Major morbidity (Clavien-Dindo >grade 2) and 30-day mortality were 14/76(18.4%) and 1/76(1.3%) respectively. There were 12(15.8%) venous occlusion including 4(5.3%) acute occlusions. Overall 6-month, 1-year and 2-year primary patency was 89.1%, 92.5% and 92.3% respectively. 1-year primary patency of primary repair was superior to end-to-end anastomosis and interposition graft (primary repair 100%, end-to-end anastomosis 81.8%, interposition graft 66.7%, p = 0.045). Pairwise comparison also demonstrated superior 1-year patency of primary repair (adjusted p = 0.037). There was no significant difference between the cumulative venous patency for each venous reconstruction method: primary repair 84±6%, end-to-end anastomosis 75±11% and interposition graft 76±15% (p = 0.561).

Conclusion

1-year primary venous patency of primary repair is superior to end-to-end anastomosis and interposition graft.

Actual 10-year survivors and 10-year recurrence free survivors after primary liver resection for hepatocellular carcinoma in the 21st century: A single institution contemporary experience

BACKGROUND

At present, the majority of outcome studies of survival of hepatocellular carcinoma (HCC) post-liver resection (post-LR) present actuarial survival data, which often results in overestimation of survival. We sought to evaluate the actual 10-year survival post-LR for HCC and identify variables that are associated with long-term survival.

METHODS

We performed a retrospective review of 600 consecutive patients who underwent primary LR for HCC from 2000 to 2010 at our institution. Twenty-eight patients (4.7%) with 90-day mortality and 125 patients who were lost to follow-up within 10 years were excluded leaving 447 patients who met the study criteria.

RESULTS

There were 140 actual 10-year survivors of which 57 (40.7%) had a recurrence within 10 years. The actual 10-year overall survival (OS) rate of the 447 patients was 31.5% and the actual 10-year recurrence-free survival (RFS) was 18.6%. Multivariate analyses demonstrated that only age >65 years (OR, 0.29; p < .001) (OR, 0.973; p = .041) and presence of cirrhosis (OR. 0.37; p = .005) (OR, 0.31; p = .001) were independent factors negatively associated with actual 10-year OS and actual 10-year RFS, respectively.

CONCLUSION

Approximately one-third of patients will survive over 10 years after LR for HCC. Amongst these 10-year survivors, 41% had developed recurrent cancer within 10-years of follow-up.