The Effect of the Intraoperative Blood Loss and Intraoperative Blood Transfusion on the Short-Term Outcomes and Prognosis of Colorectal Cancer: A Propensity Score Matching Analysis

Outcomes of robotic versus laparoscopic-assisted surgery in patients with rectal cancer: a systematic review and meta-analysis

PURPOSE

Robotic-assisted rectal surgery (RARS) and Laparoscopic-assisted rectal surgery are the two techniques that are increasingly used for rectal cancer, and both have their advantages and disadvantages. This meta-analysis will analyze the outcomes of both techniques to determine their relative performance and suitability.

METHODS

An extensive search was carried out on PubMed, Cochrane, Scopus, Embase, and Google Scholar, followed by a meta-analysis of all randomized controlled trials (RCTs) to assess both approaches for rectal cancer.

RESULTS

This meta-analysis is comprised of fifteen RCTs. The conversion to open surgery (RR = 0.53, 95% CI: 0.38-0.74, P = 0.0002) was significantly lower in the RARS group. The outcomes like anastomotic leak, postoperative ileus, postoperative urinary retention (POUR), surgical site infection (SSI), and intra-abdominal abscess showed no significant difference between the two groups. The reoperation rate (RR = 0.56, 95% CI: 0.34-0.95, P = 0.03) was lower in the robotic group. High heterogeneity was obtained when pooling data on operative time, length of hospital stay, and blood loss. Oncological outcomes, including local recurrence, the number of harvested lymph nodes (LN) and distal resection margin showed no significant distinction among both groups, while the positive circumferential resection margin (CRM) (RR = 0.67, 95% CI: 0.49-0.91, P = 0.01) was lower in the RARS group. RARS demonstrated a significantly higher rate of total mesorectal excision (TME) (RR = 1.07, 95% CI: 1.01-1.14, P = 0.03).

CONCLUSION

RARS is safe and feasible for rectal cancer patients and may be superior or equivalent to Laparoscopic-assisted rectal surgery, but high-standard, large-scale trials are required to determine the best approach.

Perioperative Blood Transfusions and Cancer Progression: A Narrative Review

PURPOSE OF REVIEW

To examine the most recent evidence about known controversies on the effect of perioperative transfusion on cancer progression.

RECENT FINDINGS

Laboratory evidence suggests that transfusion-related immunomodulation can be modified by blood management and storage practices, but it is likely of less intensity than the effect of the surgical stress response. Clinical evidence has questioned the independent effect of blood transfusion on cancer progression for some cancers but supported it for others. Despite major changes in surgery and anesthesia, cancer surgery remains a major player in perioperative blood product utilization. Prospective data is still required to strengthen or refute existing associations. Transfusion-related immunomodulation in cancer surgery is well-documented, but the extent to which it affects cancer progression is unclear. Associations between transfusion and cancer progression are disease-specific. Increasing evidence shows autologous blood transfusion may be safe in cancer surgery.

Personalized prediction of postoperative complication and survival among Colorectal Liver Metastases Patients Receiving Simultaneous Resection using machine learning approaches: A multi-center study

BACKGROUND

To predict clinical important outcomes for colorectal liver metastases (CRLM) patients receiving colorectal resection with simultaneous liver resection by integrating demographic, clinical, laboratory, and genetic data.

METHODS

Random forest (RF) models were developed to predict postoperative complications and major complications (binary outcomes), as well as progression-free survival (PFS) and overall survival (OS) (time-to-event outcomes) of the CRLM patients based on data from two hospitals. The models were validated on an external dataset from an independent hospital. The clinical utility of the models was assessed via decision curve analyses (DCA).

RESULTS

There were 1067 patients included in survival prediction analyses and 1070 patients included in postoperative complication prediction analyses. The RF models provided an assessment of the model contributions of features for outcomes and suggested KRAS, BRAF, and MMR status were salient for the PFS or OS predictions. RF model of PFS showed that the Brier scores at 1-, 3-, and 5-year PFS were 0.213, 0.202 and 0.188; and the AUCs of 1-, 3- and 5-year PFS were 0.702, 0.720 and 0.743. RF model of OS revealed that Brier scores of 1-,3-, and 5-year OS were 0.040, 0.183 and 0.211; and the AUCs of 1-, 3- and 5-year OS were 0.737, 0.706 and 0.719. RF model for postoperative complication resulted in an AUC of 0.716 and a Brier score of 0.196. DCA curves clearly demonstrated that the RF models for these outcomes exhibited a superior net benefit across a wide range of threshold probabilities, signifying their favorable clinical utility. The RF models consistently exhibited robust performance in both internal cross-validation and external validation. The individualized risk profile predicted by the models closely aligned with the actual survival outcomes observed for the patients. A web-based tool (https://kanli.shinyapps.io/CRLMRF/) was provided to demonstrate the practical use of the prediction models for new patients in the clinical setting.

CONCLUSION

The predictive models and a web-based tool for personalized prediction demonstrated a moderate predictive performance and favorable clinical utilities on several key clinical outcomes of CRLM patients receiving simultaneous resection, which could facilitate the clinical decision-making and inform future interventions for CRLM patients.

Effect of intraoperative blood loss on postoperative complications and prognosis of patients with colorectal cancer: A meta‑analysis

The purpose of the present study was to evaluate whether the amount of intraoperative blood loss (IBL) affects the complications and prognosis of patients with colorectal cancer (CRC). The PubMed, EMBASE and the Cochrane Library databases were used to search for eligible studies from inception to November 30, 2020. Hazard ratios (HRs) and 95% confidence intervals (Cls) were pooled up. The overall survival (OS) and disease-free survival (DFS) were compared between the larger IBL group and the smaller IBL group. The present study was performed with RevMan 5.3 (The Cochrane Collaboration). A total of seven studies involving 1,540 patients with CRC were included in the present study. The smaller IBL group had a higher rate of OS (HR=1.45, 95% CI=1.17 to 1.8, P=0.0007) and a higher rate of DFS (HR=1.76, 95% CI=1.40 to 2.21, P<0.00001). Furthermore, the larger IBL group had a higher rate of postoperative complications than the smaller IBL group (odds ratio=2.06, 95% CI=1.72 to 2.15, P<0.00001). In conclusion, a smaller IBL was associated with better OS and DFS, and a lower risk of postoperative complications compared with a larger IBL in patients with CRC, suggesting that surgeons should pay more attention during perioperative management and surgical operation to reduce IBL.

Streamlining robotic-assisted abdominoperineal resection

BACKGROUND

Robot-assisted surgery has proven to be a safe and feasible approach for the management of rectal cancer, including abdominoperineal resection (APR). However, it often incurs longer operative times and higher costs. This study aimed to overcome these limitations by adopting a synchronous approach utilizing an optimized team composition.

METHODS

Data on patients who underwent robot-assisted APR at our facility between June 2022 and June 2023 were analyzed. The key points of the optimized approach included the following: At the start of the surgery, the surgeon performed an anococcygeal ligament resection from the perineal side while the bedside assistants set up the ports. Then, through console manipulation, the presacral fascia, elevated by previously placed gauze, was easily and safely incised, providing access to the perineal region.

RESULTS

A total of nine patients were included in this study. The median operation time was 231 min, and the intraoperative blood loss was 170 ml. The operation time was reduced to 167.5 min, and the blood loss was 80.5 ml in cases without a trainee. Surgical site infections, classified as Clavien-Dindo grade II complications, were observed in two cases, but no obvious urinary or erectile dysfunction was observed.

CONCLUSION

The study results indicate that the challenges associated with APR can be efficiently addressed without requiring additional personnel by streamlining team composition and the synchronous approach. This optimization strategy minimizes the need for a larger surgical team, while maximizing the utilization of surgical time and resources.

Association of perioperative allogeneic blood transfusions and long-term outcomes following radical surgery for gastric and colorectal cancers: systematic review and meta-analysis of propensity-adjusted observational studies

BACKGROUND

Previous meta-analyses reporting significant associations between perioperative allogeneic blood transfusions and poor prognosis in gastric cancer or colorectal cancer had a high risk of confounding bias. This meta-analysis explored this issue using observational studies that applied propensity score analysis.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for manuscripts published between 2013 and 2022. Studies applying propensity score analysis were included to investigate the association between perioperative allogeneic blood transfusions and prognosis in gastric cancer or colorectal cancer after radical surgery. Pooled HRs for overall survival and disease-free survival were calculated using a fixed-effect model or random-effect model according to heterogeneity.

RESULTS

Twelve retrospective cohort studies with 17 607 patients reported were included. Ten studies applied propensity score matching and two applied inverse probability of treatment weighting using propensity score. A total of 5962 patients were analysed after propensity score adjustment. After propensity score adjustment, perioperative allogeneic blood transfusions did not correlate with disease-free survival in gastric cancer (HR 1.16; 95 per cent c.i. 0.96-1.39; heterogeneity was assessed by the chi-squared test and inconsistency index (I2) = 57 per cent) or colorectal cancer (HR 1.12; 95 per cent c.i. 0.84-1.49; I2 = 54 per cent). However, after propensity score adjustment, perioperative allogeneic blood transfusions were significantly associated with worse overall survival in gastric cancer (HR 1.20; 95 per cent c.i. 1.08-1.32; I2 = 25 per cent) and colorectal cancer (HR 1.40; 95 per cent c.i. 1.06-1.85; I2 = 52 per cent). Subgroup analyses showed that perioperative allogeneic blood transfusions did not correlate with overall survival in colorectal cancer when major postoperative complications were balanced after propensity score.

CONCLUSION

Perioperative allogeneic blood transfusion is not correlated with recurrence of gastric cancer and colorectal cancer. Perioperative allogeneic blood transfusions are significantly associated with worse overall survival in gastric cancer and colorectal cancer, which may be attributable to unbalanced major postoperative complications after propensity score adjustment.

The effect of carbon nanoparticles staining on lymph node tracking in colorectal cancer: A propensity score matching analysis

Purpose

The aim of this study was to evaluate the effect of carbon nanoparticles staining (CNS) on colorectal cancer (CRC) surgery, lymph node tracing and postoperative complications using propensity score matching (PSM).

Method

Patients who were diagnosed with CRC and underwent surgery were retrospectively collected from a single clinical center from Jan 2011 to Dec 2021. Baseline characteristics, surgical information and postoperative information were compared between the CNS group and the non-CNS group. PSM was used to eliminate bias.

Results

A total of 6,886 patients were enrolled for retrospective analysis. There were 2,078 (30.2%) patients in the CNS group and 4,808 (69.8%) patients in the non-CNS group. After using 1: 1 ratio PSM to eliminate bias, there were 2,045 patients left in each group. Meanwhile, all of their baseline characteristics were well matched and there was no statistical significance between the two groups (P > 0.05). In terms of surgical information and short-term outcomes, the CNS group had less intraoperative blood loss (P < 0.01), shorter operation time (P < 0.01), shorter postoperative hospital stay (P < 0.01), less metastatic lymph nodes (P = 0.013), more total retrieved lymph nodes (P < 0.01), more lymphatic fistula (P = 0.011) and less postoperative overall complications (P < 0.01) than the non-CNS group before PSM. After PSM, the CNS group had less intraoperative blood loss (P = 0.004), shorter postoperative hospital stay (P < 0.01) and more total retrieved lymph nodes (P < 0.01) than the non-CNS group. No statistical difference was found in other outcomes (P > 0.05).

Conclusion

Preoperative CNS could help the surgeons detect more lymph nodes, thus better determining the patient's N stage. Furthermore, it could reduce intraoperative blood loss and reduce the hospital stay.

Generating real-world evidence compatible with evidence from randomized controlled trials: a novel observational study design applicable to surgical transfusion research

BACKGROUND

Numerous observational studies have revealed an increased risk of death and complications with transfusion, but this observation has not been confirmed in randomized controlled trials (RCTs). The "transfusion kills patients" paradox persists in real-world observational studies despite application of analytic methods such as propensity-score matching. We propose a new design to address this long-term existing issue, which if left unresolved, will be deleterious to the healthy generation of evidence that supports optimized transfusion practice.

METHODS

In the new design, we stress three aspects for reconciling observational studies and RCTs on transfusion safety: (1) re-definition of the study population according to a stable hemoglobin range (gray zone of transfusion decision; 7.5-9.5 g/dL in this study); (2) selection of comparison groups according to a trigger value (last hemoglobin measurement before transfusion; nadir during hospital stay for control); (3) dealing with patient heterogeneity according to standardized mean difference (SMD) values. We applied the new design to hospitalized older patients (aged ≥60 years) undergoing general surgery at four academic/teaching hospitals. Four datasets were analyzed: a base population before (Base Match-) and after (Base Match+) propensity-score matching to simulate previous observational studies; a study population before (Study Match-) and after (Study Match+) propensity-score matching to demonstrate effects of our design.

RESULTS

Of 6141 older patients, 662 (10.78%) were transfused and showed high heterogeneity compared with those not receiving transfusion, particularly regarding preoperative hemoglobin (mean: 11.0 vs. 13.5 g/dL) and intraoperative bleeding (≥500 mL: 37.9% vs. 2.1%). Patient heterogeneity was reduced with the new design; SMD of the two variables was reduced from approximately 100% (Base Match-) to 0% (Study Match+). Transfusion was related to a higher risk of death and complications in Base Match- (odds ratio [OR], 95% confidence interval [CI]: 2.68, 1.86-3.86) and Base Match+ (2.24, 1.43-3.49), but not in Study Match- (0.77, 0.32-1.86) or Study Match+ (0.66, 0.23-1.89).

CONCLUSIONS

We show how choice of study population and analysis could affect real-world study findings. Our results following the new design are in accordance with relevant RCTs, highlighting its value in accelerating the pace of transfusion evidence generation and generalization.

Does Intraoperative Blood Loss Affect the Short-Term Outcomes and Prognosis of Gastric Cancer Patients After Gastrectomy? A Meta-Analysis

Purpose

The purpose of the current meta-analysis was to analyze whether intraoperative blood loss (IBL) influenced the complications and prognosis of gastric cancer patients after gastrectomy.

Methods

We systematically searched the PubMed, Embase and Cochrane library databases on November 29, 2021. The Newcastle-Ottawa scale was used to evaluate the quality of included studies. This meta-analysis uses RevMan 5.3 for data analysis.

Results

A total of nine retrospective studies were included in this meta-analysis, involving 4653 patients. In terms of short-term outcomes, the Larger IBL group has a higher complication rate (OR = 1.94, 95% CI, 1.44 to 2.61, P < 0.0001) and a longer operation time (OR = 77.60, 95% CI, 41.95 to 113.25, P < 0.0001) compared with the smaller IBL group, but the Larger IBL group had higher total retrieved lymph nodes (OR = 3.68, 95% CI, 1.13 to 6.24, P = 0.005). After pooling up all the HRs, the Larger IBL group has worse overall survival (OS) (HR = 1.80, 95% CI, 1.27 to 2.56, P = 0.001) and disease-free survival (DFS) (HR = 1.48, 95% CI, 1.28 to 1.72, P < 0.00001).

Conclusion

Larger IBL increased operation time and postoperative complications, and decreased OS and DFS of gastric cancer patients. Therefore, surgeons should be cautious about IBL during operation.