Early experience with pure laparoscopic donor hepatectomy: comparison with open donor hepatectomy and non-donor laparoscopic hepatectomy

BACKGROUND

Pure laparoscopic donor hepatectomy (L-DH) has seen a rise in uptake in recent years following the popularization of minimally invasive modality for major hepatobiliary surgery. Our study aimed to determine the safety and compare the perioperative outcomes of L-DH with open donor hepatectomy (O-DH) and laparoscopic non donor hepatectomy (L-NDH) based on our single institution experience.

METHODS

Eighty of 113 laparoscopic hemi-hepatectomies performed between 2015 and 2022 met study inclusion criteria. Of these, 11 were L-DH. PSM in a 1:2 ratio of L-DH versus L-NDH and 1:1 ratio of L-DH versus O-DH were performed, identifying patients with similar baseline clinicopathological characteristics.

RESULTS

After 2:1 matching, the L-DH cohort were significantly younger (P < 0.001) and had lower ASA scores (P < 0.001) than the L-NDH cohort. L-DH was associated with a longer median operating time (P < 0.001) and shorter median postoperative stay (P < 0.001) than L-NDH. After 1:1 matching, there were no significant differences in baseline demographic between the L-DH and O-DH cohorts. L-DH was associated with lower median blood loss (P = 0.040) and shorter length of stay compared to O-DH (P = 0.004). There were no significant differences in recipient outcomes for both cohorts.

CONCLUSION

L-DH can be adopted safely by surgeons experienced in L-NDH and ODH. It is associated with decreased blood loss and shorter length of stay compared to O-DH.

Critical appraisal of surgical margins according to KRAS status in liver resection for colorectal liver metastases: Should surgical strategy be influenced by tumor biology?

BACKGROUND

KRAS mutation is a negative prognostic factor for colorectal liver metastases. Several studies have investigated the resection margins according to KRAS status, with conflicting results. The aim of the study was to assess the oncologic outcomes of R0 and R1 resections for colorectal liver metastases according to KRAS status.

METHODS

All patients who underwent resection for colorectal liver metastases between 2010 and 2015 with available KRAS status were enrolled in this multicentric international cohort study. Logistic regression models were used to investigate the outcomes of R0 and R1 colorectal liver metastases resections according to KRAS status: wild type versus mutated. The primary outcomes were overall survival and disease-free survival.

RESULTS

The analysis included 593 patients. KRAS mutation was associated with shorter overall survival (40 vs 60 months; P = .0012) and disease-free survival (15 vs 21 months; P = .003). In KRAS-mutated tumors, the resection margin did not influence oncologic outcomes. In multivariable analysis, the only predictor of disease-free survival and overall survival was primary tumor location (P = .03 and P = .03, respectively). In KRAS wild-type tumors, R0 resection was associated with prolonged overall survival (74 vs 45 months, P < .001) and disease-free survival (30 vs 17 months, P < .001). The multivariable model confirmed that R0 resection margin was associated with prolonged overall survival (hazard ratio = 1.43, 95% confidence interval: 1.01-2.03) and disease-free survival (hazard ratio = 1.42; 95% confidence interval: 1.06-1.91).

CONCLUSIONS

KRAS-mutated colorectal liver metastases showed more aggressive tumor biology with inferior overall survival and disease-free survival after liver resection. Although R0 resection was not associated with improved oncologic outcomes in the KRAS-mutated tumors group, it seems to be of paramount importance for achieving prolonged long-term survival in KRAS wild-type tumors.

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.

Intraoperative blood transfusion does not impact overall and recurrence-free survival after curative hepatectomy for hepatocellular carcinoma: A propensity-score-matched and inverse probability of treatment-weighted study

INTRODUCTION

Our primary objective was to determine if receiving intraoperative blood transfusion was a significant prognostic factor for overall and recurrence-free survival after curative resection of hepatic cellular carcinoma (HCC).

METHODOLOGY

Between 2001 and 2018, 1092 patients with histologically proven primary HCC who underwent curative liver resection were retrospectively reviewed. Primary study endpoints were recurrence-free survival (RFS) and overall survival (OS). The main analysis was undertaken using propensity-score matching (PSM) to minimize confounding and selection biases in the comparison of patients with or without transfusion.

RESULTS

There were 220 patients who received and 666 patients who did not receive intraoperative blood transfusion. The PSM cohort consisted of 163 pairs of patients. After PSM, the only perioperative outcome that appeared to significantly affect whether patients would receive blood transfusion was median blood loss (p = 0.001). In the PSM cohort, whether patients received blood transfusion was neither associated with OS (p = 0.759) nor RFS (p = 0.830). When the volume of blood transfusion was analyzed as a continuous variable, no significant dose-response relationship between blood transfusion volume and HR for OS and RFS was noted.

CONCLUSION

Intraoperative blood transfusion had no significant impact on the survival outcomes in patients who receive curative resection in primary HCC.

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.

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.

Long-Term Outcomes of Perioperative Versus Neoadjuvant Chemotherapy for Resectable Colorectal Liver Metastases: An International Multicentre Propensity-Score Matched Analysis with Stratification by Contemporary Risk-Scoring

BACKGROUND

There is still debate regarding the principal role and ideal timing of perioperative chemotherapy (CTx) for patients with upfront resectable colorectal liver metastases (CRLM). This study assesses long-term oncological outcomes in patients receiving neoadjuvant CTx only versus those receiving neoadjuvant combined with adjuvant therapy (perioperative CTx).

METHODS

International multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010 and 2015. Characteristics and outcomes were compared before and after propensity score matching (PSM). Primary endpoints were long-term oncological outcomes, such as recurrence-free survival (RFS) and overall survival (OS). Furthermore, stratification by the tumour burden score (TBS) was applied.

RESULTS

Of 967 patients undergoing hepatectomy, 252 were analysed, with a median follow-up of 45 months. The unmatched comparison revealed a bias towards patients with neoadjuvant CTx presenting with more high-risk patients (p = 0.045) and experiencing increased postoperative complications ≥Clavien-Dindo III (20.9% vs. 8%, p = 0.003). Multivariable analysis showed that perioperative CTx was associated with significantly improved RFS (hazard ratio [HR] 0.579, 95% confidence interval [CI] 0.420-0.800, p = 0.001) and OS (HR 0.579, 95% CI 0.403-0.834, p = 0.003). After PSM (n = 180 patients), the two groups were comparable regarding baseline characteristics. The perioperative CTx group presented with a significantly prolonged RFS (HR 0.53, 95% CI 0.37-0.76, p = 0.007) and OS (HR 0.58, 95% CI 0.38-0.87, p = 0.010) in both low and high TBS patients.

CONCLUSIONS

When patients after resection of CRLM are able to tolerate additional postoperative CTx, a perioperative strategy demonstrates increased RFS and OS in comparison with neoadjuvant CTx only in both low and high-risk situations.

A systematic review and network meta-analysis of outcomes after open, mini-laparotomy, hybrid, totally laparoscopic, and robotic living donor right hepatectomy

BACKGROUND

A systematic review and network meta-analysis was performed to compare outcomes after living donor right hepatectomy via the following techniques: conventional open (Open), mini-laparotomy (Minilap), hybrid (Hybrid), totally laparoscopic (Lap), and robotic living donor right hepatectomy (Robotic).

METHODS

PubMed, EMBASE, Cochrane, and Scopus were searched from inception to August 2021 for comparative studies of patients who underwent living donor right hepatectomy.

RESULTS

Nineteen studies comprising 2,261 patients were included. Operation time was longer in Lap versus Minilap and Open (mean difference 65.09 min, 95% confidence interval 3.40-126.78 and mean difference 34.81 minutes, 95% confidence interval 1.84-67.78), and in Robotic versus Hybrid, Lap, Minilap, and Open (mean difference 144.72 minutes, 95% confidence interval 89.84-199.59, mean difference 113.24 minutes, 95% confidence interval 53.28-173.20, mean difference 178.33 minutes, 95% confidence interval 105.58-251.08 and mean difference 148.05 minutes, 95% confidence interval 97.35-198.74, respectively). Minilap and Open were associated with higher blood loss compared to Lap (mean difference 258.67 mL, 95% confidence interval 107.00-410.33 and mean difference 314.11 mL, 95% confidence interval 143.84-484.37) and Robotic (mean difference 205.60 mL, 95% confidence interval 45.92-365.28 and mean difference 261.04 mL, 95% confidence interval 84.26-437.82). Open was associated with more overall complications compared to Minilap (odds ratio 2.60, 95% confidence interval 1.11-6.08). Recipient biliary complication rate was higher in Minilap and Open versus Hybrid (odds ratio 3.91, 95% confidence interval 1.13-13.55 and odds ratio 11.42, 95% confidence interval 2.27-57.49), and lower in Open versus Minilap (OR 0.07, 95% confidence interval 0.01-0.34).

CONCLUSION

Minimally invasive donor right hepatectomy via the various techniques is safe and feasible when performed in high-volume centers, with no major differences in donor complication rates and comparable recipient outcomes once surgeons have mounted the learning curve.

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.

Liver resection in elderly patients with extensive CRLM: Are we offering an adequate treatment? A propensity score matched analysis

BACKGROUND

Data on the management of elderly patients with extensive colorectal liver metastases (CRLM) are scarce and conflicting. This study assesses differences in management and long-term oncological outcomes between older and younger patients with CRLM and a high Tumour Burden Score (TBS).

METHODS

International multicentre retrospective study on patients with CRLM and a category 3 TBS, submitted to liver resection. Patients were divided into two groups according to their age (younger and older than 75) and were compared using propensity score matching (PSM) analysis and multivariable regression models. Differences in management and oncological outcomes including recurrence-free survival (RFS) and overall survival (OS) were assessed.

RESULTS

The study included 386 patients, median follow-up was 48 months. The unmatched comparison revealed a higher ASA score (p = 0.035), less synchronous CRLM (47% vs 68%, p = 0.003), a lower median number of lesions (1 vs 3, p = 0.004) and less perioperative chemotherapy (CTx) (66% vs 88%, p < 0.001) in the elderly group. Despite the absence of CTx being an independent predictor of decreased RFS and OS (HR 0.760, p = 0.044 and HR 0.719, p = 0.049, respectively), the elderly group still received less CTx (OR 0.317, p = 0.001) than the younger group. After PSM (n = 100 patients), the two groups were comparable, however, CTx administration was still significantly lower in the elderly group.

CONCLUSION

Liver resection should be considered in patients aged 75 and older, even if they present with extensive liver disease. Despite CTx being associated with improved oncological outcomes, a large percentage of elderly patients with CRLM are undertreated.

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.

Perioperative chemotherapy versus surgery alone for resectable colorectal liver metastases: an international multicentre propensity score matched analysis on long-term outcomes according to established prognostic risk scores

BACKGROUND

There is still uncertainty regarding the role of perioperative chemotherapy (CTx) in patients with resectable colorectal liver metastases (CRLM), especially in those with a low-risk of recurrence.

METHODS

Multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010-2015. Patients were divided into two groups according to whether they received perioperative CTx or not and were compared using propensity score matching (PSM) analysis. Then, they were stratified according to prognostic risk scores, including: Clinical Risk Score (CRS), Tumour Burden Score (TBS) and Genetic And Morphological Evaluation (GAME) score.

RESULTS

The study included 967 patients with a median follow-up of 68 months. After PSM analysis, patients with perioperative CTx presented prolonged overall survival (OS) in comparison with the surgery alone group (82.8 vs 52.5 months, p = 0.017). On multivariable analysis perioperative CTx was an independent predictor of increased OS (HR 0.705, 95%CI 0.705-0.516, p = 0.029). The benefits of perioperative CTx on survival were confirmed in patients with CRS and TBS scores ≤2 (p = 0.022 and p = 0.020, respectively) and in patients with a GAME score ≤1 (p = 0.006).

CONCLUSION

Perioperative CTx demonstrated an increase in OS in patients with CRLM. Patients with a low-risk of recurrence seem to benefit from systemic treatment.

Evolution and trends in the adoption of laparoscopic liver resection in Singapore: Analysis of 300 cases

ABSTRACT Introduction: The introduction of laparoscopic surgery has changed abdominal surgery. We evaluated the evolution and changing trends associated with adoption of laparoscopic liver resection (LLR) and the experience of a surgeon without prior LLR experience. Methods: A retrospective review of 310 patients who underwent LLR performed by a single surgeon from 2011 to 2020 was conducted. Exclusion criteria were patients who underwent laparoscopic liver surgeries such as excision biopsy, local ablation, drainage of abscesses and deroofing of liver cysts. There were 300 cases and the cohort was divided into 5 groups of 60 patients. Results: There were 288 patients who underwent a totally minimally invasive approach, including 28 robotic-assisted procedures. Open conversion occurred for 13 (4.3%) patients; the conversion rate decreased significantly from 10% in the initial period to 3.3% subsequently. There were 83 (27.7%) major resections and 131 (43.7%) resections were performed for tumours in the difficult posterosuperior location. There were 152 (50.7%) patients with previous abdominal surgery, including 52 (17.3%) repeat liver resections for recurrent tumours, and 60 patients had other concomitant operations. According to the Iwate criteria, 135 (44.7%) were graded as high/expert difficulty. Major morbidity (>grade 3a) occurred in 12 (4.0%) patients and there was no 30-day mortality. Comparison across the 5 patient groups demonstrated a significant trend towards older patients, higher American Society of Anesthesiologists (ASA) score, increasing frequency of LLR with previous abdominal surgery, increasing frequency of portal hypertension and huge tumours, decreasing blood loss and decreasing transfusion rate across the study period. Surgeon experience (≤60 cases) and Institut Mutualiste Montsouris (IMM) high grade resections were independent predictors of open conversion. Open conversion was associated with worse perioperative outcomes such as increased blood loss, transfusion rate, morbidity and length of stay. Conclusion: LLR can be safely adopted for resections of all difficulty grades, including major resections and for tumours located in the difficult posterosuperior segments, with a low open conversion rate. Keywords: Laparoscopic hepatectomy, laparoscopic liver resection, robotic hepatectomy, robotic liver resection, Singapore

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.

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.

Comparison between short and long-term outcomes after minimally invasive versus open primary liver resections for hepatocellular carcinoma: A 1:1 matched analysis

BACKGROUND

This study aims to compare the short- and long-term outcomes of patients undergoing minimally invasive liver resection (MILR) versus open liver resection (OLR) for nonrecurrent hepatocellular carcinoma (HCC).

METHODS

Review of 204 MILR and 755 OLR without previous LR performed between 2005 and 2018. 1:1 coarsened exact matching (CEM) and 1:1 propensity-score matching (PSM) were performed.

RESULTS

Overall, 190 MILR were well-matched with 190 OLR by PSM and 86 MILR with 86 OLR by CEM according to patient baseline characteristics. After PSM and CEM, MILR was associated with a significantly longer operation time [230 min (interquartile range [IQR], 145-330) vs. 160 min (IQR, 125-210), p < .001] [215 min (IQR, 135-295) vs. 153.5 min (120-180), p < .001], shorter postoperative stay [4 days (IQR, 3-6) vs. 6 days (IQR, 5-8), p = .001)] [4 days (IQR, 3-5) vs. 6 days (IQR, 5-7), p = .004] and lower postoperative morbidity [40 (21%) vs. 67 (35.5%), p = .003] [16 (18.6%) vs. 27 (31.4%), p = .036] compared to OLR. MILR was also associated with a significantly longer median time to recurrence (70 vs. 40.3 months, p = .014) compared to OLR after PSM but not CEM. There was no significant difference in terms of overall survival and recurrence-free survival.

CONCLUSION

MILR is associated with superior short-term postoperative outcomes and with at least equivalent long-term oncological outcomes compared to OLR for HCC.

Repeat hepatectomy versus radiofrequency ablation in management of recurrent hepatocellular carcinoma: an average treatment effect analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with high rates of recurrence post-resection. Repeat hepatectomy (RH) and radiofrequency ablation (RFA) are the mainstays for managing recurrent HCC following initial curative resection. This retrospective study aims to determine the average treatment effect of RH and RFA in patients with recurrent HCC.

PATIENTS AND METHODS

From 2000 to 2016, a total of 219 consecutive patients with recurrent HCC who underwent either RH or RFA were included in the study. The analysis was performed using inverse probability of treatment weighting (IPTW), and propensity score-matched (PSM) methods.

RESULTS

The minor and major post-operative morbidity after propensity score-matched analysis for the RH group was 30.0% and 6.0%, respectively, and 19.2% and 0.0% (p = 0.1006), respectively, for the RFA group. After propensity score matching, the median OS for RH and RFA was 85.5 (IQR, 33.5-not reached) and 53.3 months (IQR, 27.5-not reached) (p = 0.8474), respectively. There was no significant difference in 90-day mortality between both groups (p = 0.1287). RH showed improved long-term overall survival over RFA at the third [71.3% versus 65.7% (p = 0.0432)], fifth [59.9% versus 45.4% (p = 0.0271)] and tenth [35.4% versus 32.2% (p = 0.0132)] year follow-up, respectively. Median time to recurrence was 11.1 (IQR, 5.0-33.2) and 28.0 months (IQR, 9.1-not reached) (p = 0.0225) for the RFA and RH group, respectively.

CONCLUSIONS

RH confers a late survival benefit compared with RFA for patients with recurrent HCC despite a higher morbidity rate.

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.

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.

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.

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.

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.

Impact of liver cirrhosis on the difficulty of minimally-invasive liver resections: a 1:1 coarsened exact-matched controlled study

INTRODUCTION

The impact of liver cirrhosis on the difficulty of minimal invasive liver resection (MILR) remains controversial and current difficulty scoring systems do not take in to account the presence of cirrhosis as a significant factor in determining the difficulty of MILR. We hypothesized that the difficulty of MILR is affected by the presence of cirrhosis. Hence, we performed a 1:1 matched-controlled study comparing the outcomes between patients undergoing MILR with and without cirrhosis including the Iwate system and Institut Mutualiste Montsouris (IMM) system in the matching process.

METHODS

Between 2006 and 2019, 598 consecutive patients underwent MILR of which 536 met the study inclusion criteria. There were 148 patients with cirrhosis and 388 non-cirrhotics. One-to-one coarsened exact matching identified approximately exact matches between 100 cirrhotic patients and 100 non-cirrhotic patients.

RESULTS

Comparison between MILR patients with cirrhosis and non-cirrhosis in the entire cohort demonstrated that patients with cirrhosis were associated with a significantly increased open conversion rate, transfusion rate, need for Pringles maneuver, postoperative, stay, postoperative morbidity and postoperative 90-day mortality. After 1:1 coarsened exact matching, MILR with cirrhosis were significantly associated with an increased open conversion rate (15% vs 6%, p = 0.03), operation time (261 vs 238 min, p  < 0.001), blood loss (607 vs 314 mls, p  = 0.002), transfusion rate (22% vs 9%, p  = 0.001), need for application of Pringles maneuver (51% vs 34%, p  = 0.010), postoperative stay (6 vs 4.5 days, p  = 0.004) and postoperative morbidity (26% vs 13%, p  = 0.029).

CONCLUSION

The presence of liver cirrhosis affected both the intraoperative technical difficulty and postoperative outcomes of MILR and hence should be considered an important parameter to be included in future difficulty scoring systems for MILR.

A single institution experience with robotic and laparoscopic distal pancreatectomies

Backgrounds/Aims

This study aims to describe our experience with minimally-invasive distal pancreatectomies, with emphasis on the comparison between robotic distal pancreatectomy (RDP) and laparoscopic distal pancreatectomy (LDP).

Methods

Retrospective review of 102 consecutive RDP and LDP from 2006 to 2019 was performed.

Results

There were 27 and 75 patients who underwent RDP and LDP, respectively. There were 12 (11.8%) open conversions and 16 (15.7%) patients had major (>grade 2) morbidities. Patients who underwent RDP had significantly higher rates of splenic preservation (44.4% vs. 13.3%, p=0.002), higher rates of splenic-vessel preservation (40.7% vs. 9.3%, p=0.001), higher median difficulty score (5 vs. 3, p=0.002) but longer operation time (385 vs. 245 minutes, p<0.001). The rate of open conversion tended to be lower with RDP (3.7% vs. 14.7%, p=0.175).

Conclusions

In our institution practice, both RDP and LDP were safe and effective. The use of RDP appeared to be complementary to LDP, allowing us to perform more difficult procedures with comparable postoperative outcomes.

Validation of the clinical utility of 4 guidelines in the initial triage of mucinous cystic lesions of the pancreas based on cross-sectional imaging: Experience with 188 surgically-treated patients

INTRODUCTION

Over the years, several guidelines have been introduced to guide management of mucinous pancreatic cystic neoplasms (mPCN). In this study, we aimed to evaluate and compare the clinically utility of the Sendai-06, Fukuoka-12, Fukuoka-17 and European-18 guidelines in predicting malignancy of mPCN.

METHODS

One hundred and eighty-eight patients with mucinous cystic neoplasms (MCN) or intraductal papillary mucinous neoplasm (IPMN) who underwent surgery were retrospectively reviewed and classified under the 4 guidelines. Malignancy was defined as high grade dysplasia and invasive carcinoma.

RESULTS

Raised CA19-9>37U/ml, enhancing mural nodule≥5 mm and main pancreatic duct≥10 mm were significantly associated with malignancy on multivariate analysis. Increasing number of high risk features, absolute indications (European-18), worrisome risk or relative indications (European-18) were significantly associated with an increased likelihood of malignancy. The positive predictive values (PPV) of high risk features for Sendai-06, Fukuoka-12, Fukuoka-17 and absolute indications (European-18) for malignancy were 53%, 76%, 78% and 78% respectively. The negative predictive values (NPV) of the Sendai-06, Fukuoka-12 and Fukuoka-17 were 100%, while that of the European-18 was 92%. Risk of malignancy for patients with ≥4 worrisome features (Fukuoka-17) and ≥3 relative indications (European-18) was 66.7% and 75.0% respectively.

CONCLUSIONS

All 4 guidelines studied were useful in the initial triage of mPCN for the risk stratification of malignancy. The Fukuoka-17 had the highest PPV and NPV.

Impact of First Assistant Surgeon Experience on the Perioperative Outcomes of Laparoscopic Hepatectomies

Introduction: This study aims to evaluate the impact of first assistant surgeon experience on the outcomes of laparoscopic hepatectomies in a university-affiliated teaching hospital. Methods: This is a retrospective study comparing outcomes of laparoscopic hepatectomies with first assistant surgeons of varying experience levels. Three hundred and eighty-five consecutive laparoscopic hepatectomies performed in a tertiary university-affiliated teaching hospital from 2012 to 2018 were included and stratified into three cohorts-Group 1 in which assistants were residents, Group 2 for fellows, and Group 3 for attendings. Baseline clinicopathologic variables and outcome measures were analyzed using the augmented inverse probability of treatment weighting approach, which is a propensity score-based method that combines aspects of covariate adjustment and inverse probability weighting. Results: Group 3 comprised a greater proportion of advanced- and expert-level surgeries based on the Iwate criteria; 33.8%, 32.2%, and 46.0% of patients underwent advanced- and expert-level surgeries in Groups 1, 2, and 3, respectively. Group 3 had consistently higher operative times as well as more frequent use and longer duration of Pringle's maneuver (P < .05). The median operative times for Groups 1, 2, and 3 were 195, 195, and 290 minutes, respectively. Pringle's maneuver was applied in 26.9%, 33.9%, and 60.2% of patients with a corresponding median duration of 35, 36, and 45 minutes, respectively. None of the other perioperative and postoperative outcomes demonstrated statistically significant differences. Conclusion: With an appropriate selection of cases, participation of residents as first assistants in laparoscopic hepatectomies can be encouraged without compromise in perioperative outcomes.

Changing trends and outcomes associated with the adoption of minimally-invasive pancreato-biliary surgery: Contemporary experience of a 'self-taught' early adopter in Southeast Asia

Background:

Minimally-invasive pancreato-biliary surgery (MIPBS) is increasingly reported worldwide. This study examines the changing trends, safety and outcomes associated with the adoption of MIPBS based on a contemporary experience of an early adopter in Southeast Asia.

Methods:

Retrospective review of 114 consecutive patients who underwent MIPBS by a single surgeon over 86 months from 2011. The study population was stratified into three equal groups of 38 patients. Comparison was also performed between minimally-invasive pancreato surgery (MIPS) and minimally-invasive biliary surgery (MIBS).

Results:

There were 70 MIPS and 44 MIBS. Sixty-three cases (55.3%) were performed using robotic assistance and fourteen (12.3%) were hybrid procedures with open reconstruction. Forty-four (38.6%) procedures were performed for malignancy. There were 8 (7.0%) open conversions and median operation time was 335 (range, 60–930) min. There were nine extended pancreatectomies including seven involving vascular reconstructions. Major morbidity (>Grade 2) occurred in 20 (17.5%) patients including 6 (5.3%) reoperations and there was no mortality. Comparison across the three groups demonstrated that with increasing experience, there was a significant trend in a higher proportion of higher ASA score patients, increasing frequency of procedures requiring anastomosis and increasing the use of robotic assistance without significant difference in key perioperative outcomes such as open conversion rate, morbidity and hospital stay. Comparison between MIPS and MIBS demonstrated that MIPS was associated with significantly longer operation time, increased blood loss, increased transfusion rate, longer hospital stay, increased readmission rate and increased morbidity.

Conclusion:

MIPBS can be safely adopted today with a low open conversion rate.

Laparoscopic distal pancreatosplenectomy for isolated blunt traumatic pancreatic laceration: A case report and review of current literature

Pancreatic injuries are often associated with trauma and occur most commonly in combination with other solid organ injuries. Management strategies for pancreatic injuries include conservative, endoscopic, percutaneous and surgical intervention. Literature on the laparoscopic approach to management of pancreatic trauma is rare and poorly reviewed. We describe a case report of successful and uncomplicated laparoscopic distal pancreatosplenectomy (LDP) for a patient suffering from isolated traumatic pancreatic tail transection. A literature review was performed with regards to the indications for intervention and different modalities of treatment for traumatic pancreatic lacerations. A review and comparison was also made between the scarce pre-existing reports of the laparoscopic approach to pancreatic resection in the setting of trauma. The laparoscopic approach to pancreatic resection, in the setting of trauma, can be considered as a viable alternative to open surgery. Moving forward, further studies with larger patient numbers will be needed to compare the outcomes between the open and laparoscopic approach.

Effect of surgical delay on survival outcomes in patients undergoing curative resection for primary hepatocellular carcinoma: Inverse probability of treatment weighting using propensity scores and propensity score adjustment

BACKGROUND

The evidence is conflicting regarding the effect of delays from the time of diagnosis to surgery on the survival in patients with hepatocellular carcinoma. We sought to investigate the impact of time to surgery on overall survival for patients who underwent curative resection for primary hepatocellular carcinoma.

METHODS

We performed a retrospective review of all patients who underwent liver resection for primary hepatocellular carcinoma between the years 2000 and 2015. Using 30-, 60-, and 90-day cutoffs, we investigated the effect of time to surgery on survival outcomes by dichotomizing the patients and using inverse probability of treatment weighting to ensure comparability. We also investigated time to surgery in prognostic subgroups by modeling the statistical interaction between time to surgery and the relevant prognostic variable in multivariable Cox models.

RESULTS

A total of 863 patients underwent liver resection for primary hepatocellular carcinoma during the study period. Using 30-, 60-, and 90-day cutoffs, time to surgery did not have a significant bearing on overall survival. For elderly patients (>70 years), patients with Child-Pugh B liver disease, American Society of Anesthesiologists status 2/3, tumor size >5cm, tumor size ≥10cm and presence of extrahepatic invasion, hazard ratio decreased and overall survival improved as time to surgery increased. However, for patients with liver cirrhosis or portal hypertension, increasing time to surgery was found to portend higher risks of death.

CONCLUSION

Time to surgery does not have a significant bearing on overall survival, and modest delays even appear to be associated with improved survival in specific subsets of patients. The importance of these findings is that patients with hepatocellular carcinoma should be fully optimized before and not rushed to surgery because of concerns of tumor progression and a diminished survival.

Preoperative Predictors Including the Role of Inflammatory Indices in Predicting Early Recurrence After Re-resection for Recurrent Hepatocellular Carcinoma

BACKGROUND

Repeat liver resection (RLR) for recurrent HCC (rHCC) is a widely accepted treatment modality. However, early recurrence rate is high, frequently resulting in futile resection. We performed this study to evaluate preoperative factors, including the value of inflammatory indices, in predicting early (<1 year) recurrence in patients who underwent RLR for rHCC. This may help clinicians better select patients for RLR, while excluding cases in which RLR for rHCC would likely be futile.

METHODS

This is a retrospective study of 80 patients where 90 operative cases of RLR and 84 cases of early recurrence (<1 year) post-RLR were evaluated. Preoperative predictors of early recurrence and overall survival (OS) were assessed.

RESULTS

There were 31 (34.4%) early recurrences with a 5-year OS of 38.9%. Elevated platelet-to-lymphocyte ratio (PLR) >103.6 was a significant independent preoperative predictor of both early recurrence, relative risk (RR) 4.284 (P = 0.001) and OS, RR 2.139 (P = 0.027), while alphafetoprotein (AFP) ≥ 200 was a significant independent preoperative predictor of early recurrence only, RR 11.655 (P = 0.030). Patients were followed-up at a median of 14.3 months with 54.8% developing intrahepatic recurrences and 19.4% developing extrahepatic recurrences.

CONCLUSION

Both, elevated PLR and AFP ≥ 200 were independent predictors of early (<1 year) recurrence after RLR for rHCC, while only an elevated PLR was an independent preoperative prognosticators of overall survival. Indication for RLR should be carefully discussed in patients with relapsed HCC with an elevated PLR, due to the potential of early recurrence and poor overall survival.

First experience with robotic pancreatoduodenectomy in Singapore

INTRODUCTION

Recent studies reported that laparoscopic pancreatoduodenectomy (LPD) is associated with superior perioperative outcomes compared to the open approach. However, concerns have been raised about the safety of LPD, especially during the learning phase. Robotic pancreatoduodenectomy (RPD) has been reported to be associated with a shorter learning curve compared to LPD. We herein present our initial experience with RPD.

METHODS

A retrospective review of a single-institution prospective robotic hepatopancreaticobiliary (HPB) surgery database of 70 patients identified seven consecutive RPDs performed by a single surgeon in 2016-2017. These were matched at a 1:2 ratio with 14 open pancreatoduodenectomies (OPDs) selected from 77 consecutive pancreatoduodenectomies performed by the same surgeon between 2011 and 2017.

RESULTS

Seven patients underwent RPD, of which five were hybrid procedures with open reconstruction. There were no open conversions. Median operative time was 710.0 (range 560.0-930.0) minutes. Two major morbidities (> Grade 2) occurred: one gastrojejunostomy bleed requiring endoscopic haemostasis and one delayed gastric emptying requiring feeding tube placement. There were no pancreatic fistulas, reoperations or 90-day/in-hospital mortalities in the RPD group. Comparison between RPD and OPD demonstrated that RPD was associated with a significantly longer operative time. Compared to open surgery, there was no significant difference in estimated blood loss, blood transfusion, postoperative stay, pancreatic fistula rates, morbidity and mortality rates, R0 resection rates, and lymph node harvest rates.

CONCLUSION

Our initial experience demonstrates that RPD is feasible and safe in selected patients. It can be safely adopted without any compromise in patient outcomes compared to the open approach.

Minimally invasive surgery for gastric gastrointestinal stromal tumors

Minimally invasive surgery has been increasingly performed for gastric gastrointestinal stromal tumors (GIST). In this review we discuss and summarize the current evidence on minimally invasive surgery for gastric GISTs. Laparoscopic resection for gastric GIST has been consistently shown to be associated with superior perioperative outcomes with no compromise in oncological outcomes when compared to open resection in numerous retrospective case-control studies. It has also been shown to be safe and feasible for large tumors or tumors located in unfavorable sites. However, to date, there remains a lack of level 1 evidence from prospective randomized control trials in support of laparoscopic resection.

Short-Term Outcomes of Extended Pancreatectomy: A Single-Surgeon Experience

Background/Aims

The International Study Group of Pancreatic Surgery recently published a consensus statement on the definition of extended pancreatectomy (EP). We aimed to determine the safety profile and short-term outcomes of EP compared to standard pancreatectomy (SP). To mitigate surgeon bias, only pancreatectomies performed by a single surgeon were included.

Methods

Ninety consecutive patients who underwent pancreatectomy by a single surgeon over a period of 5 years and who met our study criteria were classified into an SP or an EP group. Sixty-two patients underwent pancreaticoduodenectomy (PD), including total pancreatectomy, and 28 patients underwent distal pancreatectomy.

Results

The 25 patients who underwent EP had significantly increased operation time, estimated blood loss, postoperative intensive care unit (ICU) transfer, and postoperative stay compared to the 65 patients who underwent SP. There was 1 (1.1%) 30-day mortality and 4 (4.4%) in-hospital mortalities. Postoperative morbidity and mortality were similar between both groups. Subgroup analysis of the patients who underwent PD demonstrated that the EP group (n = 22) had significantly increased operation time and postoperative ICU transfers.

Conclusion

Although patients who underwent EP experienced significantly increased operative time, blood loss, and postoperative stay, they did not experience significantly higher postoperative morbidity or mortality compared to patients who underwent SP.

Secondary stent-in-stent self-expanding metallic stent placement for early stent occlusion due to mucosal oedema in the gastrojejunal anastomosis after palliative subtotal gastrectomy for locally advanced gastric cancer

Herein, we report a case of early in-stent occlusion due to the ingrowth of soft oedematous mucosal tissue through the lattices of an uncovered stent, which was used for palliation of a postoperative gastrojejunal anastomotic stricture. The in-stent occulsion was treated with the deployment of a second stent, which was covered, within the first stent. This led to successful resolution of the occlusion.

Validation of the MSKCC Gastrointestinal Stromal Tumor Nomogram and Comparison with Other Prognostication Systems: Single-Institution Experience with 289 Patients

PURPOSE

To validate the Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram in a single-institution cohort of patients with gastrointestinal stromal tumors (GISTs), and to compare its predictive accuracy against other established risk classification systems, including the National Institutes of Health (NIH), Armed Forces Institute of Pathology (AFIP), and Joensuu criteria.

METHODS

We retrospectively reviewed 289 patients who underwent surgical resection for primary localized GISTs without adjuvant imatinib therapy and compared the actuarial recurrence-free survival (RFS) with the predicted RFS.

RESULTS

Tumors >5 cm in size, with high mitotic index, and which had ruptured were significantly associated with recurrent disease. The 2-year RFS was 77.2 % [95 % confidence interval (CI) 71.6-81.8], and the 5-year RFS was 67.9 % (95 % CI 61.7-73.4). The concordance probability of the nomogram of 2-year RFS was 0.71 (SE 0.02), and 5-year RFS was 0.71 (SE 0.19). The 2-year and 5-year MSKCC nomogram probability calculations and the AFIP criteria gave a better estimation of RFS compared to the NIH (p < 0.001) and Joensuu (p < 0.001) criteria. There was no significant difference between the predictive accuracy of the nomogram compared to the AFIP criteria.

CONCLUSIONS

The MSKCC nomogram slightly underestimated the probability of RFS after surgical resection of GISTs. It was associated with a significantly better predictive accuracy compared to the NIH and Joensuu. This study suggests that there is a wider than expected prognostic divergence between gastric GISTs versus GISTs arising from the small intestine.

Cloquet's node trumps imaging modalities in the prediction of pelvic nodal involvement in patients with lower limb melanomas in Asian patients with palpable groin nodes

Patients with clinically palpable lymph node metastases to the groin are treated with groin dissection to control local disease and stage the malignancy. However, the extent of nodal dissection required to optimize survival rate is controversial.

AIM

To evaluate the approach to the extent of nodal dissection in advanced lower limb melanomas with clinically palpable inguinal nodes; to review survival outcomes based on the extent of nodal dissection and nodal disease.

MATERIALS AND METHODS

A prospectively maintained database of 12 patients with lower limb melanoma was analyzed. Cloquet's node was assessed based on the frozen section result which guided the decision to proceed to iliac-obturator dissection. The correlation of the results of the Cloquet's nodes and radiological imaging to the final histological outcome of groin nodal dissection were compared.

RESULTS

The positive predictive value (PPV) of radiological imaging in identifying pelvic nodal disease was 60%. PPV of a positive or indeterminate frozen section result of Cloquet's node was 71.4%. Notably, all patients with a positive frozen section result for the Cloquet's node had positive pelvic nodal disease. Median DFS for all patients is 26 months (range 3-68 months) and the median OS for all patients is 28.5 months (range 5-68 months). Median DFS for node negative patients was 28 months (range 24-68 months). Median DFS for node positive patients was 20 months (range 3-36 months).

CONCLUSION

Cloquet's node was shown to be superior to radiological imaging and should be preferentially used to decide on the extent of nodal dissection.

Systematic review and meta-analysis comparing the surgical outcomes of invasive intraductal papillary mucinous neoplasms and conventional pancreatic ductal adenocarcinoma

OBJECTIVE

The aim of this study was to summarize the current literature comparing the surgical outcomes of invasive intraductal papillary mucinous neoplasms (IPMN(INV)) and conventional pancreatic ductal adenocarcinomas (PDAC) in order to determine the differences in disease characteristics and prognosis.

METHODS

Systematic review of the literature yielded 12 comparative studies reporting the clinicopathological characteristics and overall survival (OS) of 1,450 patients with IPMN(INV) with 19,304 patients with conventional PDAC.

RESULTS

IPMN(INV) had a significantly lower likelihood of tumors extending beyond the pancreas [27.6 vs. 94.3 %; T4 vs. T1: odds ratio (OR) 0.111, 95 % confidence intervals (CI) 0.057-0.214], nodal metastasis (45.4 vs. 62.9 %: OR 0.507, 95 % CI 0.347-0.741), positive margin (14.2 vs. 28.3 %; OR 0.438, 95 % CI 0.322-0.596), perineural invasion (49.2 vs. 76.5 %; OR 0.304, 95 % CI 0.106-0.877) and vascular invasion (25.2 vs. 45.7 % OR 0.417, 95 % CI 0.177-0.980) when compared with PDAC. The 5-year OS of IPMN(INV) was significantly better than PDAC [31.4 vs. 12.4 %: hazard ratio (HR) 0.659, 95 % CI 0.574-0.756]. The tubular subtype had a poorer 5-year OS and demonstrated significantly more aggressive features such as nodal metastases, vascular invasion, and perineural invasion compared with the colloid subtype.

CONCLUSION

IPMN(INV) were significantly more likely to present at an earlier stage and were less likely to demonstrate nodal involvement, perineural invasion and vascular invasion. When controlled for stage, IPMN(INV) had an improved OS when compared with PDAC in the early stages.

A systematic review and meta-analysis of the clinicopathologic characteristics of cystic versus solid pancreatic neuroendocrine neoplasms

INTRODUCTION

Cystic pancreatic neuroendocrine neoplasms (PNENs) are rare neoplasms, and presently, it is uncertain whether their behavior is similar or distinct from their solid counterparts. This study aimed to review systematically the present literature to compare the clinicopathologic characteristics of cystic PNENs versus their solid counterparts to determine whether cystic PNENs are likely to be a distinct entity from solid PNENs.

METHODS

Comparative studies of solid versus cystic PNENs studies were reviewed. Cystic and solid PNENs were compared on the basis of several clinicopathologic characteristics.

RESULTS

Seven nonrandomized case control studies compared 152 cystic versus 915 solid PNENs. Pooled analysis demonstrated that the likelihood of PNENs to be located in the head/uncinate of the pancreas was lower for cystic than solid neoplasms (27.7% vs 45.5%, odds ratio [OR] 0.452, 95% confidence interval [95% CI] 0.304-0.673, P < .001). Cystic PNENs were less likely to be functional (14% vs 24.4%, OR 0.405, 95% CI 0.221-0.742, P = .003) and were more likely to be benign/uncertain rather than malignant compared with solid PNENs (90.3% vs 65.9%, OR 3.151, 95% CI 1.297-7.652, P = .011). Cystic PNENs were more likely to have a mitotic count <2 per 10 hpf and a Ki67 index <2% (93.3% vs 72.7%, OR 4.897, 95% CI 2.139-11.209, P < .001 and 82.4% vs 54.1%, OR 4.079, 95% CI 2.177-7.641, P < .001), respectively. Cystic neoplasms were also less likely to have regional lymph node metastases than solid neoplasms (11.2% vs 28.9%, OR 0.387, 95% CI 0.219-0.685, P = .001).In this meta-analysis, there was no difference in the 5-year overall survival and 5-year disease-free survival between cystic vs solid PNENs (92.0% vs 86.8%, P .214) and (98.1% vs 83.9%, P = .185).

CONCLUSION

These findings suggest that cystic PNENs tend to be biologically less aggressive compared with their solid counterparts; more data, however, with respect to molecular analysis are required to establish whether cystic and solid PNENs were distinct pathologic entities.

A systematic review and meta-analysis comparing laparoscopic versus open gastric resections for gastrointestinal stromal tumors of the stomach

BACKGROUND

This study is a systematic review and meta-analysis that compares the short- and long-term outcomes of laparoscopic gastric resection (LR) versus open gastric resection (OR) for gastric gastrointestinal stromal tumors (GISTs).

METHODS

Comparative studies reporting the outcomes of LR and OR for GIST were reviewed.

RESULTS

A total of 11 nonrandomized studies reviewed 765 patients: 381 LR and 384 OR. A higher proportion of high-risk tumors and gastrectomies were in the OR compared with LR (odds ratio, 3.348; 95 % CI, 1.248-8.983; p = .016) and (odds ratio, .169; 95 % CI, .090-.315; p < .001), respectively. Intraoperative blood loss was significantly lower in the LR group [weighted mean difference (WMD), -86.508 ml; 95 % CI, -141.184 to -31.831 ml; p < .002]. The LR group was associated with a significantly lower risk of minor complications (odds ratio, .517; 95 % CI, .277-.965; p = .038), a decreased postoperative hospital stay (WMD, -3.421 days; 95 % CI, -4.737 to -2.104 days; p < .001), a shorter time to first flatus (WMD, -1.395 days; 95 % CI, -1.655 to -1.135 days; p < .001), and shorter time for resumption of oral intake (WMD, -1.887 days; 95 % CI, -2.785 to -.989 days; p < .001). There was no statistically significant difference between the two groups with regard to operation time (WMD, 5.731 min; 95 % CI, -15.354-26.815 min; p = .594), rate of major complications (odds ratio, .631; 95 % CI, .202-1.969; p = .428), margin positivity (odds ratio, .501; 95 % CI, .157-1.603; p = .244), local recurrence rate (odds ratio, .629; 95 % CI, .208-1.903; p = .412), recurrence-free survival (RFS) (odds ratio, 1.28; 95 % CI, .705-2.325; p = .417), and overall survival (OS) (odds ratio, 1.879; 95 % CI, .591-5.979; p = .285).

CONCLUSIONS

LR results in superior short-term postoperative outcomes without compromising oncological safety and long-term oncological outcomes compared with OR.