Impact of type and severity of postoperative complications on long-term outcomes after colorectal liver metastases resection

Pretreatment red blood cell distribution width as a predictive marker for postoperative complications after laparoscopic pancreatoduodenectomy

BACKGROUND

Red blood cell distribution width (RDW) is associated with the development and progression of various diseases.

AIM

To explore the association between pretreatment RDW and short-term outcomes after laparoscopic pancreatoduodenectomy (LPD).

METHODS

A total of 804 consecutive patients who underwent LPD at our hospital between March 2017 and November 2021 were retrospectively analyzed. Correlations between pretreatment RDW and clinicopathological characteristics and short-term outcomes were investigated.

RESULTS

Patients with higher pretreatment RDW were older, had higher Eastern Cooperative Oncology Group scores and were associated with poorer short-term outcomes than those with normal RDW. High pretreatment RDW was an independent risk factor for postoperative complications (POCs) (hazard ratio = 2.973, 95% confidence interval: 2.032-4.350, P < 0.001) and severe POCs of grade IIIa or higher (hazard ratio = 3.138, 95% confidence interval: 2.042-4.824, P < 0.001) based on the Clavien-Dino classification system. Subgroup analysis showed that high pretreatment RDW was an independent risk factor for Clavien-Dino classification grade IIIb or higher POCs, a comprehensive complication index score ≥ 26.2, severe postoperative pancreatic fistula, severe bile leakage and severe hemorrhage. High pretreatment RDW was positively associated with the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio and was negatively associated with albumin and the prognostic nutritional index.

CONCLUSION

Pretreatment RDW was a special parameter for patients who underwent LPD. It was associated with malnutrition, severe inflammatory status and poorer short-term outcomes. RDW could be a surrogate marker for nutritional and inflammatory status in identifying patients who were at high risk of developing POCs after LPD.

Short-Term Surgical Outcomes After Robotic Liver Surgery: A Propensity-Score Matched Analysis With Conventional Open Liver Surgery at a High-Volume Centre in Denmark

BACKGROUND

The aim of this study was to investigate the perioperative outcomes of robotic liver surgery (RLS) and Open liver surgery (OLS) in a centre with a high number of operations.

METHODS

A 1:1 propensity score matched (PSM) analysis of a retrospective database of RLS and OLS was performed. Cumulative sum (CUSUM) analysis was performed to identify learning curves.

RESULT

After PSM analysis, operative time was significantly longer in the RLS group (p < 0.001). Estimated blood loss was significantly lower in the RLS group (p < 0.001). Transfusion rates were significantly lower in the RLS group. The length of hospital stay was shorter in the RLS group (3.5vs6.3 days, p < 0.001). Readmission rates were significantly lower in the RLS group (p < 0.049). CUSUM analysis showed a learning curve for at least 8 low-intermediate RLS procedures and 27 advanced-Expert RLS procedures.

CONCLUSIONS

RLS has many advantages, including being safe to perform, less blood loss and faster postoperative recovery compared with OLS.

Prognostic Impact of Post-operative Infectious Complications in Gastric Cancer Patients Receiving Neoadjuvant Chemotherapy: Post Hoc Analysis of a Randomized Controlled Trial, JCOG0501

PURPOSE

Post-operative infectious complication (IC) is a well-known negative prognostic factor, while showing neoadjuvant chemotherapy (NAC) may cancel out the negative influence of IC. This analysis compared the clinical impacts of IC according to the presence or absence of NAC in gastric cancer patients enrolled in the phase III clinical trial (JCOG0501) which compared upfront surgery (arm A) and NAC followed by surgery (arm B) in type 4 and large type 3 gastric cancer.

METHODS

The subjects were 224 patients who underwent R0 resection out of 316 patients enrolled in JCOG0501. The prognoses of the patients with or without ICs in each arm were investigated by univariable and multivariable Cox regression analyses.

RESULTS

There were 21 (20.0%) IC occurrences in arm A and 15 (12.6%) in arm B. In arm A, the overall survival (OS) of patients with ICs was slightly worse than those without IC (3-year OS, 57.1% in patients with ICs, 79.8% in those without ICs; adjusted hazard ratio (95% confidence interval), 1.292 (0.655-2.546)). In arm B, patients with ICs showed a trend of better survival than those without ICs (3-year OS, 80.0% in patients with IC, 74.0% in those without IC; adjusted hazard ratio, 0.573 (0.226-1.456)).

CONCLUSION

This study could not indicate the negative prognostic influence of ICs in gastric cancer patients receiving NAC, which might be canceled by NAC. To build exact evidence, further investigation with prospective and large numbers of data might be expected.

Postoperative Complications Result in Poor Oncological Outcomes: What Is the Evidence?

The majority of patients with solid tumors undergo a curative resection of their tumor burden. However, the reported rate of postoperative complications varies widely, ranging from 10% to 70%. This narrative review aims to determine the impact of postoperative complications on recurrence and overall survival rates following elective cancer surgeries, thereby providing valuable insights into perioperative cancer care. A systematic electronic search of published studies and meta-analyses from January 2000 to August 2023 was conducted to examine the effect of postoperative complications on long-term survival after cancer surgeries. This comprehensive search identified fifty-one eligible studies and nine meta-analyses for review. Recurrence-free survival (RFS) and overall survival (OS) rates were extracted from the selected studies. Additionally, other oncological outcomes, such as recurrence and cancer-specific survival rates, were noted when RFS and OS were not reported as primary outcomes. Pooled hazard ratios and 95% confidence intervals were recorded from the meta-analyses, ensuring the robustness of the data. The analysis revealed that long-term cancer outcomes progressively worsen, from patients with no postoperative complications to those with minor postoperative complications (Clavien-Dindo grade ≤ II) and further to those with major postoperative complications (Clavien-Dindo grade III-IV), irrespective of cancer type. This study underscores the detrimental effect of postoperative complications on long-term oncological outcomes, particularly after thoracoabdominal surgeries. Importantly, we found a significant gap in the data regarding postoperative complications in surface and soft tissue surgical procedures, highlighting the need for further research in this area.

Combined Resection Approaches: Decision Making for Synchronous Resection, Timing of Staged Intervention to Optimize Outcome

Advancement in systemic and regional radiation therapy, surgical technique, and anesthesia has provided a path for increased long-term survival and potential cure for more patients with stage IV rectal cancer in recent years. When patients have resectable disease, the sequence for surgical resection is classified in three strategies: classic, simultaneous, or combined, and reversed. The classic approach consists of rectal cancer resection followed by metastatic disease at a subsequent operation. Simultaneous resection addresses both rectal and metastatic disease in a single surgery. The reversed approach treats metastatic disease first, followed by the primary tumor in several months. Simultaneous resection is appropriate for selected patients to avoid delay of definitive surgery, and reduce number of surgeries, hospital stay, and cost to the health care system. It may also improve patients' psychological effect. Multidisciplinary discussions including colorectal and liver surgeons to review patients' baseline medical conditions, tumor biology and behavior, and disease burden and distribution is imperative to guide proper patient selection for simultaneous resection and perioperative treatments.

Effects of evidence-based nursing on surgical site wound infections in patients undergoing surgery for liver cancer: A meta-analysis

This study aimed to systematically evaluate the impact of evidence-based nursing (EBN) on perioperative wound infections and postoperative complications in patients undergoing surgery for liver hepatocellular carcinoma (LIHC). Randomised controlled trials (RCTs) on the application of EBN on patients receiving LIHC surgery were searched in PubMed, Web of Science, Cochrane Library, Embase, Wanfang, China Biomedical Literature Database and China National Knowledge Infrastructure from the inception of each database to September 2023. Studies were screened and evaluated by two investigators based on inclusion and exclusion criteria, and data were extracted from the final included literature. RevMan 4.0 was used for data analysis. Overall, 15 RCTs involving 1374 patients with LIHC were included, with 687 in the EBN group and 687 in the conventional care group. The analysis revealed that the incidence of wound infections (odds ratio [OR] = 0.32, 95% confidence interval [CI]: 0.18-0.56, p < 0.001) and postoperative complications (OR = 0.22, 95% CI: 0.15-0.31, p < 0.001) was significantly lower in the EBN group than in the conventional care group. The available evidence suggests that nursing strategies for EBN applied in the perioperative period in patients with LIHC receiving surgery can effectively reduce the incidence of wound infections and postoperative complications and promote postoperative recovery.

Risk Factors for Postoperative Complications Following Resection of Colorectal Liver Metastases and the Impact on Long-Term Survival: A Population-Based National Cohort Study

BACKGROUND

Postoperative complications (POCs) following resection of colorectal liver metastases (CRLM) are common. The objective of this study was to evaluate risk factors for developing complications and their impact on survival considering prognostic factors of the primary tumor, metastatic pattern and treatment in a well-defined national cohort.

METHODS

Patients treated with resection for CRLM that was also radically resected for their primary colorectal cancer (diagnosed in 2009-2013) were identified in Swedish national registers. Liver resections were categorized according to extent of surgery (Category I-IV). Risk factors for developing POCs as well as prognostic impact of POCs were evaluated in multivariable analyses. A subgroup analysis of minor resections was performed to evaluate POCs after laparoscopic surgery.

RESULTS

POCs were registered for 24% (276/1144) of all patients after CRLM resection. Major resection was a risk factor for POCs in multivariable analysis (IRR 1.76; P = 0.001). Comparing laparoscopic and open resections in the subgroup analysis of small resections, 6% (4/68) in the laparoscopic group developed POCs compared to 18% (51/289) after open resection (IRR 0.32; P = 0.024). POCs were associated with a 27% increased excess mortality rate (EMRR 1.27; P = 0.044). However, primary tumor characteristics, tumor burden in the liver, extrahepatic spread, extent of liver resection and radicality had higher impact on survival.

CONCLUSION

Minimal invasive resections were associated with a decreased risk of POCs following resection of CRLM which should be considered in surgical strategy. Postoperative complications were associated with a moderate risk for inferior survival.

Minimally Invasive Anatomic Liver Resection for Hepatocellular Carcinoma Using the Extrahepatic Glissonian Approach: Surgical Techniques and Comparison of Outcomes with the Open Approach and between the Laparoscopic and Robotic Approaches

Surgical techniques and outcomes of minimally invasive anatomic liver resection (AR) using the extrahepatic Glissonian approach for hepatocellular carcinoma (HCC) are undefined. In 327 HCC cases undergoing 185 open (OAR) and 142 minimally invasive (MIAR; 102 laparoscopic and 40 robotic) ARs, perioperative and long-term outcomes were compared between the approaches, using propensity score matching. After matching (91:91), compared to OAR, MIAR was significantly associated with longer operative time (643 vs. 579 min, p = 0.028); less blood loss (274 vs. 955 g, p < 0.0001); a lower transfusion rate (17.6% vs. 47.3%, p < 0.0001); lower rates of major 90-day morbidity (4.4% vs. 20.9%, p = 0.0008), bile leak or collection (1.1% vs. 11.0%, p = 0.005), and 90-day mortality (0% vs. 4.4%, p = 0.043); and shorter hospital stay (15 vs. 29 days, p < 0.0001). On the other hand, laparoscopic and robotic AR cohorts after matching (31:31) had comparable perioperative outcomes. Overall and recurrence-free survivals after AR for newly developed HCC were comparable between OAR and MIAR, with potentially improved survivals in MIAR. The survivals were comparable between laparoscopic and robotic AR. MIAR was technically standardized using the extrahepatic Glissonian approach. MIAR was safe, feasible, and oncologically acceptable and would be the first choice of AR in selected HCC patients.

Nomogram to predict disease recurrence in patients with locally advanced rectal cancer undergoing rectal surgery after neoadjuvant therapy: retrospective cohort study

INTRODUCTION

Prognostic models can be used for predicting survival outcomes and guiding patient management. TNM staging alone is insufficient for predicting recurrence after chemoradiotherapy (CRT) and surgery for locally advanced rectal cancer. This study aimed to develop a nomogram to better predict cancer recurrence after CRT followed by total mesorectal excision (TME) and tailor postoperative management and follow-up.

MATERIALS AND METHODS

Between 2002 and 2019, data were retrospectively collected on patients with rectal adenocarcinoma. Data on sex, age, carcinoembryonic antigen (CEA) level, tumour location, induction chemotherapy, adjuvant chemotherapy, tumour downsizing, perineural invasion, lymphovascular invasion, pathological stage, resection margins (R0 versus R1), and pelvic septic complications were analysed. The variables significantly associated with cancer recurrence were used to build a nomogram that was validated in both the training and validation cohorts. Model performance was evaluated by receiver operating characteristic curve and area under the curve (AUC) analyses.

RESULTS

After applying exclusion criteria, 634 patients with rectal adenocarcinoma were included in this study. Eight factors (CEA level, adjuvant chemotherapy, tumour downsizing, perineural invasion, lymphovascular invasion, pathological stage, resection margins (R0 versus R1), and pelvic septic complications) were identified as nomogram variables. Our nomogram showed good performance with an AUC of 0.74 and 0.75 in the training and validation cohorts respectively.

CONCLUSION

Our nomogram is a simple tool for predicting cancer recurrence in patients with locally advanced rectal cancer after neoadjuvant CRT followed by TME. It provides an individual risk prediction of recurrence to tailor surveillance.

Postoperative complications predict poor outcomes only in patients with a low modified clinical score after resection of colorectal liver metastases: a retrospective cohort study

The aim was to identify the optimal criteria of postoperative complications (POCs) for predicting oncological outcomes after hepatectomy for colorectal liver metastases (CRLMs) and to investigate the variable prognostic implications of POCs according to the modified clinical score (M-CS). We identified 751 patients who underwent curative hepatic resection for CRLM between 2007 and 2018. Patients were categorized based on the M-CS. The impact of the severity [≥ Clavien-Dindo grade (C-D) III or comprehensive complication index (CCI) ≥ 26.2] or type [any infectious complications of POC (Inf-poc)] of POC on overall survival (OS) and recurrence-free survival (RFS) was assessed by univariate and multivariable analyses in different groups. Patients with a major or infectious complication were not associated with either RFS or OS in multivariable analysis of the whole cohort. However, patients with a high CCI had a worse OS (HR 1.51, P = 0.004). Among patients with low M-CS, patients with high CCI had worse OS (HR 1.49, P = 0.035) and RFS (HR 1.32, P = 0.048) than those without high CCI. In contrast, the survival disadvantage of a high CCI was not present in patients with a high M-CS. Compared to Inf-poc or major complications, a high CCI decreased long-term OS in patients treated with hepatectomy for CRLM. High CCI has a variable prognostic impact after hepatic resection for CRLM depending on the M-CS. POC is not a decisive factor to justify the use of hepatectomy for CRLM in patients with high M-CS.

Survival Study: International Multicentric Minimally Invasive Liver Resection for Colorectal Liver Metastases (SIMMILR-2)

Introduction: Study: International Multicentric Minimally Invasive Liver Resection for Colorectal Liver Metastases (SIMMILR-CRLM) was a propensity score matched (PSM) study that reported short-term outcomes of patients with CRLM who met the Milan criteria and underwent either open (OLR), laparoscopic (LLR) or robotic liver resection (RLR). This study, designated as SIMMILR-2, reports the long-term outcomes from that initial study, now referred to as SIMMILR-1. Methods: Data regarding neoadjuvant chemotherapeutic (NC) and neoadjuvant biological (NB) treatments received were collected, and Kaplan−Meier curves reporting the 5-year overall (OS) and recurrence-free survival (RFS) for OLR, LLR and RLR were created for patients who presented with synchronous lesions only, as there was insufficient follow-up for patients with metachronous lesions. Results: A total of 73% of patients received NC and 38% received NB in the OLR group compared to 70% and 28% in the LLR group, respectively (p = 0.5 and p = 0.08). A total of 82% of patients received NC and 40% received NB in the OLR group compared to 86% and 32% in the RLR group, respectively (p > 0.05). A total of 71% of patients received NC and 53% received NB in the LLR group compared to 71% and 47% in the RLR group, respectively (p > 0.05). OS at 5 years was 34.8% after OLR compared to 37.1% after LLR (p = 0.4), 34.3% after OLR compared to 46.9% after RLR (p = 0.4) and 30.3% after LLR compared to 46.9% after RLR (p = 0.9). RFS at 5 years was 12.1% after OLR compared to 20.7% after LLR (p = 0.6), 33.3% after OLR compared to 26.3% after RLR (p = 0.6) and 22.7% after LLR compared to 34.6% after RLR (p = 0.6). Conclusions: When comparing OLR, LLR and RLR, the OS and RFS were all similar after utilization of the Milan criteria and PSM. Biological agents tended to be utilized more in the OLR group when compared to the LLR group, suggesting that highly aggressive tumors are still managed through an open approach.

The Impact of Postoperative Complications on Survival after Simultaneous Resection of Colorectal Cancer and Liver Metastases

Background: The aim of this study was to investigate the impact of postoperative complications on the long-term outcomes of patients who had undergone simultaneous resection (SR) of colorectal cancer and synchronous liver metastases (SCLMs). Methods: We conducted a single-institution survival cohort study in patients with SR, collecting clinical, pathological, and postoperative complication data. The impact of these variables on overall survival (OS) and disease-free survival (DFS) was compared by log rank test. Multivariate Cox regression analysis identified independent prognostic factors. Results: Out of 243 patients, 122 (50.2%) developed postoperative complications: 54 (22.2%) major complications (Clavien–Dindo grade III–V), 86 (35.3%) septic complications, 59 (24.2%) hepatic complications. Median comprehensive complication index (CCI) was 8.70. Twelve (4.9%) patients died postoperatively. The 3- and 5-year OS and DFS rates were 60.7%, 39.5% and 28%, 21.5%, respectively. Neither overall postoperative complications nor major and septic complications or CCI had a significant impact on OS or DFS. Multivariate analysis identified the N2 stage as an independent prognostic of poor OS, while N2 stage and four or more SCLMs were independent predictors for poor DFS. Conclusion: N2 stage and four or more SCLMs impacted OS and/or DFS, while CCI, presence, type, or grade of postoperative complications had no significant impact on long-term outcomes.

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.

Impact of Postoperative Infectious Complications on Long-Term Outcomes for Patients Undergoing Simultaneous Resection for Colorectal Cancer Liver Metastases: A Propensity Score Matching Analysis

OBJECTIVE

To investigate the impact of postoperative infectious complications (POI) on the long-term outcomes of patients with colorectal cancer liver metastasis (CRLM) after simultaneous resection of colorectal cancer and liver metastases.

METHODS

Four hundred seventy-nine CRLM patients receiving simultaneous resection between February 2010 and February 2018 at our hospital were enrolled. A 1:3 propensity score matching analysis (PSM) analysis was performed to balance covariates and avoid selection bias. After PSM, 90 patients were distributed to the POI group, and 233 patients were distributed to the no POI group. A log-rank test was performed to compare the progression-free survival (PFS) and overall survival (OS) data. A multivariate Cox regression model was employed to identify prognostic factors influencing OS and PFS. A value of two-sided P<0.05 was considered statistically significant.

RESULTS

Compared to patients in the no POI group, patients in the POI group were more likely to have hepatic portal occlusion (78.9% vs. 66.3%, P=0.021), operation time ≥325 min (61.1% vs. 48.1%, P=0.026), and intraoperative blood loss ≥200 ml (81.1% vs. 67.6%, P=0.012). In multivariate analysis, intraoperative blood loss ≥200 ml (OR = 2.057, 95% CI: 1.165-3.634, P=0.013) was identified as the only independent risk factor for POI. Patients with POI had a worse PFS (P<0.001, median PFS: 7.5 vs. 12.7 months) and a worse OS (P=0.010, median OS: 38.8 vs. 59.0 months) than those without POI. After 1:3 PSM analysis, no differences in clinicopathologic parameters were detected between the POI group and the no POI group. Patients with POI had a worse PFS (P=0.013, median PFS: 7.5 vs. 11.1 months) and a worse OS (P=0.020, median OS: 38.8 vs. 59.0 months) than those without POI. Multivariate analysis showed that POI was an independent predictor for worse PFS (HR=1.410, 95% CI: 1.065-1.869, P=0.017) and worse OS (HR=1.682, 95% CI: 1.113-2.544, P=0.014).

CONCLUSIONS

POI can significantly worsen the long-term outcomes of CRLM patients receiving simultaneous resection of colorectal cancer and liver metastases and should be considered to improve postoperative management and make better treatment decisions for these patients.

Associations of Postoperative Complications Assessed by Clavien-Dindo Classification and Comprehensive Complication Index with Long-Term Overall Survival in Elderly Patients after Radical CRC Resection

Background

Advancing age is associated with high incidence of colorectal cancer (CRC) and high rates of postoperative complications (POCs). However, the impact of of POC severity — evaluated by Clavien–Dindo classification (CDC) or comprehensive complication index (CCI) — on long-term overall survival (OS) in elderly patients after radical CRC resection is not clear.

Methods

Elderly patients aged 65 years or more with CRC undergoing radical resection were retrospectively recruited. POC details were collected and evaluated using CDC grades and the CCI, blinded to patients’ other information. Risk factors for CDC grade ≥II POCs were analyzed by multivariate logistic regression. Effects of CDC grade II–IV POCs on long-term OS were analyzed via propensity-score matching (PSM) analysis followed by Kaplan–Meier curve plotting and multivariate Cox proportional-hazard regression adjusted for all potential confounders. The prognostic value of the CCI was also explored and compared with CDC grades.

Results

A total of 614 elderly patients were identified, of which 20, 106, 25, 11, and 13 cases experienced CDC grade I, II, III, IV, and V POCs, respectively. Higher age, female sex, coronary heart diseases, family history of tumors, preoperative anemia, high amount of bleeding during operation, and high positive dissected lymph–node ratio were found to be risk factors for CDC grade II–V POCs. After PSM analyses, CDC grade II–IV POCs were identified to be associated with poor long-term OS, which was also verified in the entire cohort. The CCI was also found to be significantly associated with decreased long-term OS and showed prognostic values similar to CDC grades.

Conclusion

Both CDC grades and the CCI can be used to evaluate POCs and are associated with long-term OS in elderly patients undergoing radical CRC resection.

Outcome quality standards for surgery of colorectal liver metastasis

PURPOSE

Liver metastases are the most common malignant solid liver lesions, approximately 40% of which stem from colorectal tumors. Liver resection is currently the only curative treatment for colorectal cancer liver metastases (CRLM). However, there is a lack of consensus criteria to assess the results of this treatment. In order to evaluate the quality of surgical outcomes, it is necessary to identify quality indicators (QIs) and their corresponding quality standards (QS). We propose a simple method to determine QI and QS in CRLM surgery (CRLMS) and establish acceptable quality limits (AQL) for each QI.

MATERIAL AND METHODS

A systematic review of CRLMS results published from 2006 to 2016. Clinical guidelines, consensus conferences, and publications related to the CRLMS were reviewed to identify and select QIs. Once selected, a new review of the papers including the results of at least one of the QIs was performed. Statistical process control (SPC) method was applied to calculate the QS and AQL of each QI. The limits of variability were established from mean and confidence intervals at 95% and 99.8%.

RESULTS

The most relevant QIs and its AQLs were postoperative mortality (2%, < 4.5%), overall postoperative morbidity (33%, < 41%), liver failure (5%, < 8%), postoperative hemorrhage (1%, < 3%), biliary fistula (6%, < 10%), reoperation (3%, < 6%), R1 resection margins (18%, < 25%), and overall survival at 12 and 60 months (84%, > 77%; and 34%, > 25%, respectively).

CONCLUSIONS

Despite its limitations, the present study constitutes the most extensive scientific evidence to date on QI and AQL in CRLMS and may constitute a reference in future studies.