Predictive modeling algorithms for liver metastasis in colorectal cancer: A systematic review of the current literature.

This study aims to assess the quality and performance of predictive models for colorectal cancer liver metastasis (CRCLM). A systematic review was performed to identify relevant studies from various databases. Studies that described or validated predictive models for CRCLM were included. The methodological quality of the predictive models was assessed. Model performance was evaluated by the reported area under the receiver operating characteristic curve (AUC). Of the 117 articles screened, seven studies comprising 14 predictive models were included. The distribution of included predictive models was as follows: radiomics (n = 3), logistic regression (n = 3), Cox regression (n = 2), nomogram (n = 3), support vector machine (SVM, n = 2), random forest (n = 2), and convolutional neural network (CNN, n = 2). Age, sex, carcinoembryonic antigen, and tumor staging (T and N stage) were the most frequently used clinicopathological predictors for CRCLM. The mean AUCs ranged from 0.697 to 0.870, with 86% of the models demonstrating clear discriminative ability (AUC > 0.70). A hybrid approach combining clinical and radiomic features with SVM provided the best performance, achieving an AUC of 0.870. The overall risk of bias was identified as high in 71% of the included studies. This review highlights the potential of predictive modeling to accurately predict the occurrence of CRCLM. Integrating clinicopathological and radiomic features with machine learning algorithms demonstrates superior predictive capabilities.

A reduction in hospital length of stay reduces costs for colorectal surgery: an economic evaluation of the National Surgical Quality Improvement Program in Singapore.

PURPOSE: In 2017, the National Surgical Quality Improvement Program (NSQIP) was introduced in the Department of Colorectal Surgery at Singapore General Hospital as a pilot quality improvement initiative. This study aimed to examine the cost-effectiveness of NSQIP by evaluating its effects on surgical outcomes, length of stay (LOS), and costs. METHODS: We retrospectively reviewed patients undergoing colorectal surgery (2017-2020). Patients were divided into two cohorts: pre-NSQIP (2017-2018) and post-NSQIP (2019-2020). Outcomes evaluated were 30-day postoperative complications, LOS, and costs. Total cost-savings from NSQIP intervention's impact on LOS were estimated using a decision model with a one-way sensitivity analysis. Multivariate logistic regression was performed to identify factors for prolonged LOS. RESULTS: 1905 patients underwent colorectal surgery, with 996 in the pre-NSQIP cohort and 909 in the post-NSQIP cohort. A significant reduction in overall postoperative complications of 4.7% was observed in the post-NSQIP cohort (36.5% vs. 31.8%, p = 0.029). Patients in the post-NSQIP cohort had a shorter median LOS (8.0 vs. 6.0 days, p < 0.001). The implementation of NSQIP resulted in an 8.5% decrease in prolonged LOS > 6 days (p < 0.001), saving S$0.31 million on LOS. Total costs per case were reduced by 20.8% following NSQIP (S$39,539.05 vs. S$31,311.93, p < 0.001). CONCLUSION: Implementing NSQIP has significantly reduced overall postoperative complications, LOS, and costs and achieved cost savings following colorectal surgery.

Elderly patients over 80 years undergoing colorectal cancer resection: Development and validation of a predictive nomogram for survival.

BACKGROUND: Surgery remains the primary treatment for localized colorectal cancer (CRC). Improving surgical decision-making for elderly CRC patients necessitates an accurate predictive tool. AIM: To build a nomogram to predict the overall survival of elderly patients over 80 years undergoing CRC resection. METHODS: Two hundred and ninety-five elderly CRC patients over 80 years undergoing surgery at Singapore General Hospital between 2018 and 2021 were identified from the American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) database. Prognostic variables were selected using univariate Cox regression, and clinical feature selection was performed by the least absolute shrinkage and selection operator regression. A nomogram for 1- and 3-year overall survival was constructed based on 60% of the study cohort and tested on the remaining 40%. The performance of the nomogram was evaluated using the concordance index (C-index), area under the receiver operating characteristic curve (AUC), and calibration plots. Risk groups were stratified using the total risk points derived from the nomogram and the optimal cut-off point. Survival curves were compared between the high- and low-risk groups. RESULTS: Eight predictors: Age, Charlson comorbidity index, body mass index, serum albumin level, distant metastasis, emergency surgery, postoperative pneumonia, and postoperative myocardial infarction, were included in the nomogram. The AUC values for the 1-year survival were 0.843 and 0.826 for the training and validation cohorts, respectively. The AUC values for the 3-year survival were 0.788 and 0.750 for the training and validation cohorts, respectively. C-index values of the training cohort (0.845) and validation cohort (0.793) suggested the excellent discriminative ability of the nomogram. Calibration curves demonstrated a good consistency between the predictions and actual observations of overall survival in both training and validation cohorts. A significant difference in overall survival was seen between elderly patients stratified into low- and high-risk groups (P < 0.001). CONCLUSION: We constructed and validated a nomogram predicting 1- and 3-year survival probability in elderly patients over 80 years undergoing CRC resection, thereby facilitating holistic and informed decision-making among these patients.

Clinical outcomes and cost comparison of laparoscopic versus open surgery in elderly colorectal cancer patients over 80 years.

PURPOSE: The growth of Singapore's geriatric population, coupled with the rise in colorectal cancer (CRC), has increased the number of colorectal surgeries performed on elderly patients. This study aimed to compare the clinical outcomes and costs of laparoscopic versus open elective colorectal resections in elderly CRC patients over 80 years. METHODS: A retrospective cohort study using data from the American College of Surgeons National Surgery Quality Improvement Program (ACS-NSQIP) identified patients over 80 years undergoing elective colectomy and proctectomy between 2018 and 2021. Patient demographics, length of stay (LOS), 30-day postoperative complications, and mortality rates were analysed. Cost data in Singapore dollars were obtained from the finance database. Univariate and multivariate regression models were used to determine cost drivers. The 5-year overall survival (OS) for the entire octogenarian CRC cohort with and without postoperative complications was estimated using the Kaplan-Meier curves. RESULTS: Of the 192 octogenarian CRC patients undergoing elective colorectal surgery between 2018 and 2021, 114 underwent laparoscopic resection (59.4%), while 78 underwent open surgery (40.6%). The proportion of proctectomy cases was similar between laparoscopic and open groups (24.6% vs. 23.1%, P = 0.949). Baseline characteristics, including Charlson Comorbidity Index, albumin level, and tumour staging, were comparable between both groups. Median operative duration was 52.5 min longer in the laparoscopic group (232.5 vs. 180.0 min, P < 0.001). Both groups had no significant differences in postoperative complications and 30-day and 1-year mortality rates. Median LOS was 6 days in the laparoscopic group compared to 9 days in the open group (P < 0.001). The mean total cost was 11.7% lower in the laparoscopic group (S$25,583.44 vs. S$28,970.85, P = 0.012). Proctectomy (P = 0.024), postoperative pneumonia (P < 0.001) and urinary tract infection (P < 0.001), and prolonged LOS > 6 days (P < 0.001) were factors contributing to increased costs in the entire cohort. The 5-year OS of octogenarians with minor or major postoperative complications was significantly lower than those without complications (P < 0.001). CONCLUSION: Laparoscopic resection is associated with significantly reduced overall hospitalization costs and decreased LOS compared to open resection among octogenarian CRC patients, with comparable postoperative outcomes and 30-day and 1-year mortality rates. The extended operative time and higher consumables costs from laparoscopic resection were mitigated by the decrease in other inpatient hospitalization costs, including ward accommodation, daily treatment fees, investigation costs, and rehabilitation expenditures. Comprehensive perioperative care and optimised surgical approach to mitigate the impact of postoperative complications can improve survival in elderly patients undergoing CRC resection.

Effect of preoperative oral antibiotics and mechanical bowel preparation on the prevention of surgical site infection in elective colorectal surgery, and does oral antibiotic regime matter? a bayesian network meta-analysis.

PURPOSE: Surgical site infection (SSI) impacts 5-20% of patients after elective colorectal surgery. There are varying reports on the effectiveness of oral antibiotics (OAB) with preoperative mechanical bowel preparation (MBP) in preventing SSI. We aim to determine the role of OAB and MBP in preventing SSI after elective colorectal surgery. We also determine if a specific OAB regimen will be more effective than others. METHODS: This study investigated the impact of OAB and MBP in patients undergoing elective colorectal surgery. PubMed, MEDLINE, Ovid, Cochrane Central Register of Controlled Trials, ACP Journal Club, and Embase databases were searched for randomized clinical trials (RCTs) published by June 2022. All RCTs comparing various preoperative bowel preparation regimens, including pairwise or multi-intervention comparisons, were included. To establish the role of OAB and MBP in preventing SSI, we conducted a Bayesian network meta-analysis on all RCTs. We further performed subgroup analysis to determine the most effective OAB regimen. RESULTS: Among included 46 studies with a total of 12690 patients, patients in the MBP + OAB group were less likely to have SSI than those having MBP-only (OR 0.55, 95% CrI 0.39-0.76), and without MBP and OAB (OR 0.52, 95% CrI 0.32-0.84). OAB regimen C (kanamycin + metronidazole) and A (neomycin + metronidazole) demonstrated a significantly reduced incidence of SSI, compared to regimen B (neomycin + erythromycin) with OR 0.24 (95% CrI 0.07-0.79) and 0.26 (95% CrI 0.07-0.99) respectively. CONCLUSIONS: OAB with MBP reduces the risk of SSI after elective colorectal surgery. Providing adequate aerobic and anaerobic coverage with OAB may confer better protection against SSI.

Acute hospital-community hospital care bundle for elderly orthopedic surgery patients: A propensity score-matched economic analysis.

BACKGROUND: While Singapore attains good health outcomes, Singapore's healthcare system is confronted with bed shortages and prolonged stays for elderly people recovering from surgery in acute hospitals. An Acute Hospital-Community Hospital (AH-CH) care bundle has been developed to assist patients in postoperative rehabilitation. The core concept is to transfer patients out of AHs when clinically recommended and into CHs, where they can receive more beneficial dedicated care to aid in their recovery, while freeing up bed capacities in AHs. AIM: To analyze the AH length of stay (LOS), costs, and savings associated with the AH-CH care bundle intervention initiated and implemented in elderly patients aged 75 years and above undergoing elective orthopedic surgery. METHODS: A total of 862 1:1 propensity score-matched patients aged 75 years and above who underwent elective orthopedic surgery in Singapore General Hospital (SGH) before (2017-2018) and after (2019-2021) the care bundle intervention period was analyzed. Outcome measures were AH LOS, CH LOS, hospitalization metrics, postoperative 30-d mortality, and modified Barthel Index (MBI) scores. The costs of AH inpatient hospital stay in the matched cohorts were compared using cost data in Singapore dollars. RESULTS: Of the 862 matched elderly patients undergoing elective orthopedic surgery before and after the care bundle intervention, the age distribution, sex, American Society of Anesthesiologists classification, Charlson Comorbidity Index, and surgical approach were comparable between both groups. Patients transferred to CHs after the surgery had a shorter median AH LOS (7 d vs 9 d, P < 0.001). The mean total AH inpatient cost per patient was 14.9% less for the elderly group transferred to CHs (S$24497.3 vs S$28772.8, P < 0.001). The overall AH U-turn rates for elderly patients within the care bundle were low, with a 0% mortality rate following orthopedic surgery. When elderly patients were discharged from CHs, their MBI scores increased significantly (50.9 vs 71.9, P < 0.001). CONCLUSION: The AH-CH care bundle initiated and implemented in the Department of Orthopedic Surgery appears to be effective and cost-saving for SGH. Our results indicate that transitioning care between acute and community hospitals using this care bundle effectively reduces AH LOS in elderly patients receiving orthopedic surgery. Collaboration between acute and community care providers can assist in closing the care delivery gap and enhancing service quality.

Cost-effectiveness comparison of minimally invasive, robotic and open approaches in colorectal surgery: a systematic review and bayesian network meta-analysis of randomized clinical trials.

PURPOSE: This study compares the cost-effectiveness of open, laparoscopic (LAP), laparoscopic-assisted (LAPA), hand-assisted laparoscopic (HAL), and robotic colorectal surgery using a network meta-analysis. METHODS: Randomized clinical trials (RCTs) evaluating the cost-effectiveness of comparing the five different approaches in colorectal surgery were included in a literature search until September 2022. Bayesian network meta-analysis was conducted, and surface under cumulative ranking area (SUCRA) values, odds ratio (OR), and 95% credible intervals (CrIs) were reported for total costs, surgical costs, operating time, length of stay (LOS), and postoperative outcomes. Cluster analysis was performed to examine the similarity and classification of surgical approaches into homogeneous clusters. The cophenetic correlation coefficient (cc) was evaluated to identify the most cost-effective clustering method. The primary outcomes assessed were: costs-morbidity, costs-mortality, and costs-efficacy, measuring total costs against postoperative complications, mortality rate, and LOS, respectively. RESULTS: 22 RCTs with 4239 patients were included. Open surgery had the lowest total costs, surgical costs, and operating time but the longest LOS and most postoperative complications. LOS was significantly decreased in LAP compared to open surgery (OR 0.67, 95% CrI 0.46-0.96). Robotic surgery resulted in the highest total costs, surgical costs, and most extended operative duration but the shortest LOS and lowest mortality. LAPA and robotic surgery were superior in the costs-morbidity analysis. HAL was associated with the worst costs-mortality profile. LAP, LAPA, and HAL were better in terms of costs-efficacy. CONCLUSION: Overall, LAP and LAPA are the most cost-effective approaches for colorectal surgery in terms of overall postoperative complications, mortality, and LOS.

Stenting as a bridge to surgery in obstructing colon cancer: Long-term recurrence pattern and competing risk of mortality.

BACKGROUND: Stenting as a bridge to curative surgery (SBTS) for obstructing colon cancer (OCC) has been associated with possibly worse oncological outcomes. AIM: To evaluate the recurrence patterns, survival outcomes, and colorectal cancer (CRC)-specific death in patients undergoing SBTS for OCC. METHODS: Data from 62 patients undergoing SBTS at a single tertiary centre over ten years between 2007 and 2016 were retrospectively examined. Primary outcomes were recurrence patterns, overall survival (OS), cancer-specific survival (CSS), and CRC-specific death. OS and CSS were estimated using the Kaplan-Meier curves. Competing risk analysis with cumulative incidence function (CIF) was used to estimate CRC-specific mortality with other cause-specific death as a competing event. Fine-Gray regressions were performed to determine prognostic factors of CRC-specific death. Univariate and multivariate subdistribution hazard ratios and their corresponding Wald test P values were calculated. RESULTS: 28 patients (45.2%) developed metastases after a median period of 16 mo. Among the 18 patients with single-site metastases: Four had lung-only metastases (14.3%), four had liver-only metastases (14.3%), and 10 had peritoneum-only metastases (35.7%), while 10 patients had two or more sites of metastatic disease (35.7%). The peritoneum was the most prevalent (60.7%) site of metastatic involvement (17/28). The median follow-up duration was 46 mo. 26 (41.9%) of the 62 patients died, of which 16 (61.5%) were CRC-specific deaths and 10 (38.5%) were deaths owing to other causes. The 1-, 3-, and 5-year OS probabilities were 88%, 74%, and 59%; 1-, 3-, and 5-year CSS probabilities were 97%, 83%, and 67%. The highest CIF for CRC-specific death at 60 mo was liver-only recurrence (0.69). Liver-only recurrence, peritoneum-only recurrence, and two or more recurrence sites were predictive of CRC-specific death. CONCLUSION: The peritoneum was the most common metastatic site among patients undergoing SBTS. Liver-only recurrence, peritoneum-only recurrence, and two or more recurrence sites were predictors of CRC-specific death.

Laser hemorrhoidoplasty versus conventional hemorrhoidectomy for grade II/III hemorrhoids: a systematic review and meta-analysis.

PURPOSE: This study compared the short- and long-term clinical outcomes of laser hemorrhoidoplasty (LH) vs. conventional hemorrhoidectomy (CH) in patients with grade II/III hemorrhoids. METHODS: PubMed/Medline and the Cochrane Library were searched for randomized and nonrandomized studies comparing LH against CH in grade II/III hemorrhoids. The primary outcomes included postoperative use of analgesia, postoperative morbidity (bleeding, urinary retention, pain, thrombosis), and time of return to work/daily activities. RESULTS: Nine studies totaling 661 patients (LH, 336 and CH, 325) were included. The LH group had shorter operative time (P<0.001) and less intraoperative blood loss (P<0.001). Postoperative pain was lower in the LH group, with lower postoperative day 1 (mean difference [MD], -2.09; 95% confidence interval [CI], -3.44 to -0.75; P=0.002) and postoperative day 7 (MD, -3.94; 95% CI, -6.36 to -1.52; P=0.001) visual analogue scores and use of analgesia (risk ratio [RR], 0.59; 95% CI, 0.42-0.81; P=0.001). The risk of postoperative bleeding was also lower in the LH group (RR, 0.18; 95% CI, 0.12- 0.28; P<0.001), with a quicker return to work or daily activities (P=0.002). The 12-month risks of bleeding (P>0.999) and prolapse (P=0.240), and the likelihood of complete resolution at 12 months, were similar (P=0.240). CONCLUSION: LH offers more favorable short-term clinical outcomes than CH, with reduced morbidity and pain and earlier return to work or daily activities. Medium-term symptom recurrence at 12 months was similar. Our results should be verified in future well-designed trials with larger samples.

Trends in the surgical management of rectal prolapse: An Asian experience.

BACKGROUND: Posterior compartment pelvic floor prolapse (PCPFP) leads to anatomical distortion and functional impairment. Definitive management involves surgery. Ventral mesh rectopexy (VMR) has gained increasing popularity in the West as it emerges as a durable approach. Existing literature and evidence on safety and efficacy of PCPFP surgery in the Asian population remains sparse. Our study aims to review our institution's experience in surgery for PCPFP. METHODS: All cases of PCPFP surgery in Singapore General Hospital between 2014 to 2019 were studied. RESULTS: Eighty-three patients had surgery performed for PCPFP, with the majority (83%) in the last 3 years. Median age was 63 years and 92% were female. Most patients (64%) had obstructive defecation symptoms, while the remaining had fecal incontinence, rectal bleeding, or anal discomfort. Main anatomical indication for surgery was external rectal prolapse (48%). Other indications were rectocele and/or rectal intussusception. The majority (66%) had abdominal rectopexy, while 28 underwent Delorme's procedure. Forty-five of the 50 VMRs were minimally invasive. Patients undergoing rectopexy were observed to be younger. Median length of stay was 3 days. Nine patients had early operative complications of which ileus was most common. Median length of follow-up was 12 months. The majority (93%) had initial symptom satisfaction. Eleven patients had anatomical recurrence with a median length of 9 months to development. There was no significant difference in outcomes between abdominal vs perineal approach, or laparoscopic vs robotic VMR. CONCLUSION: Surgery for PCPFP has gained acceptance in our Asian institution with good symptom improvement, alongside low morbidity and recurrence.