Winson Jianhong Tan

Background: Complex pelvic tumors and fistula-in-ano present challenging anatomical pathologies that can hinder successful surgical outcomes. Three-dimensional (3D) printed anatomical models can improve the accuracy and outcome of surgical treatments, while serving as tools for medical and patient education. This study aims to review existing literature on the application of 3D printing in colorectal surgery, with a special focus on complex pelvic tumors and fistula-in-ano. Additionally, a brief discussion of our initial experience in utilizing 3D printed models is included. Methodology: A literature review was conducted using MEDLINE/PubMed to identify randomized controlled trials (RCTs), retrospective studies, and technical reports. Five 3D-printed anatomical models were manufactured for colorectal surgeons in our center. AI was not used in the research and manuscript development. Results: A total of seven articles were identified, revealing the utility of 3D printing for improving current and future surgical management of complex pelvic tumors and fistula-in-ano through improved pre-operative planning and medical education. In addition, our initial experience exemplified the usefulness of 3D-printed anatomical models for enhancing pre-operative planning, intra-operative navigation, and patient education. Conclusion: Existing literature and our single-center experience highlight the role of 3D printing in improving the management of complex pelvic tumors and fistula-in-ano. Larger and more well-designed studies looking into operative and financial outcomes, as well as patients’ and surgeons’ experiences, may be required to further justify its clinical utility and fidelity.

Background: Sarcopenia is associated with adverse surgical outcomes. Recent literature suggested that pre-surgery prehabilitation, nutrition and β-Hydroxy β-methylbutyric acid (HMB) supplementation improve myological and functional outcomes. However, long-term outcomes remain uncertain. Thus, we aimed to analyse findings from the long-term follow-up of surgical patients undergoing oral supplementation and prehabilitation. Methods: A prospective single-centre pilot cohort study was conducted to evaluate the effects of multimodal prehabilitation using high-protein oral nutritional supplementation (HP-ONS) with HMB. Sarcopenic patients between 40 and 90 years old and undergoing gastrointestinal surgery were included from June 2022 to January 2024. Patients were followed up from two to four weeks pre-operatively to six months post-operatively. Paired Wilcoxon signed-rank tests were conducted to evaluate outcomes between time points. Results: 36 patients were included with a median age of 71.5 years (IQR: 55–90), and 50% were male. 12 (33.3%) patients were sarcopenic, while 24 (66.7%) were severely sarcopenic. No significant difference in IMAT% was observed at post-operative six months. Number of chair rise repetitions (Median:15 vs. 11, p < 0.001) and six-min walk test (Median: 387 m vs. 349 m, p = 0.020), mid-arm muscle circumference (Median: 23.7 cm vs. 22.5 cm, p = 0.013), mid-arm muscle area (Median: 44.8 cm² vs. 39.3 cm², p = 0.005), weight (Median: 51.6 kg vs. 50.8 kg, p = 0.023) and BMI (Median: 23.2 kg/m² vs. 21.8 kg/m², p = 0.025) increased significantly at six-months post-operatively from surgery. Conclusions: Our findings suggest that improvements in anthropometric and functional outcomes from prehabilitation may persist beyond the acute recovery period. If supported by future works, multimodal prehabilitation has the potential to optimise postoperative recovery amongst sarcopenic older adult surgical patients.

Purpose: In patients with acute left-sided colonic obstruction, stenting can convert an emergency operation into a semi-elective procedure. However, its use continues to be debated. We performed a cost-effective analysis using our institution’s experiences.Methods: Endoscopic, surgical, and financial details were prospectively collected for patients who presented with acute colonic obstruction and underwent stenting between 2019 and 2022. Outcomes were defined as technical/clinical success and successful surgical resection. The financial cost of stenting was compared with the expected cost without stenting.Results: Forty patients were included, with 29 undergoing definitive resection. The most common pathology was primary colon cancer (27 patients, 93%). Endoscopic stenting had high technical (90%) and clinical (83%) success rates, with low rates of complications such as perforation (2 patients, 7%) and migration (0 patients, 0%). As a bridge to surgery, the median procedure time was 226 minutes and the surgical outcomes also showed a low rate of complications (3 patients, 11%), such as anastomotic leakage (0 patients, 0%), intraabdominal abscesses (2 patients, 7%), and 30-day postoperative mortality (0 patients, 0%). The cumulative costs with colonic stenting were $32,900, while the expected costs with emergency surgery, including stoma reversal, were $40,700 (healthcare cost-savings of $7,800 per person). The difference was mainly due to the avoidance of upfront emergency surgery. The incremental cost-effectiveness ratio was 0.81, favoring colonic stenting over upfront emergency surgery.Conclusion: Colonic stenting as a bridge to surgery is safe and cost-effective for treating left-sided colonic obstruction with high success rates and low complication rates.

Background: Multimodal prehabilitation programs, which may incorporate nutritional supplementation and exercise, have been developed to combat sarcopenia in surgical patients to enhance post-operative outcomes. However, the optimal regime remains unknown. The use of beta-hydroxy beta-methylbutyrate (HMB) has beneficial effects on muscle mass and strength. However, its effect on muscle quality in the perioperative setting has yet to be established. This study aims to explore the impact of a multimodal prehabilitation program using a bundle of care that includes high-protein oral nutritional supplementation (HP ONS) with HMB and resistance exercise on muscle quality and functional outcomes in sarcopenic surgical patients. Methods: Sarcopenic adult patients undergoing elective major gastrointestinal surgeries were recruited for this pilot interventional cohort study. They were enrolled in a 2–4-week multimodal prehabilitation program comprising resistance exercise, nutritional supplementation, vitamin supplementation, comorbid optimization and smoking cessation. Participants were provided three units of HP ONS with HMB per day pre-operatively. The primary outcome was changes in intramuscular adipose tissue (IMAT) as a proxy of muscle quality, assessed using Artificial Intelligence (AI)-aided ultrasonography. Secondary outcomes include changes in anthropometric measurements and functional characteristics. Outcomes were measured before prehabilitation, after prehabilitation and 1 month post-operatively. Results: A total of 36 sarcopenic patients, with a median age of 71.5 years, were included in this study. There was an increase in the IMAT index after two weeks of prehabilitation (p = 0.032) to 1 month after surgery (p = 0.028). Among functional parameters, improvement was observed in gait speed (p = 0.01) after two weeks of prehabilitation, which returned to baseline post-operatively. The median length of hospital stay was 7 (range: 2–75) days. Conclusions: The increase in the IMAT index in a sarcopenic surgical cohort undergoing prehabilitation may be due to altered muscle metabolism in elderly sarcopenic patients. A prehabilitation regime in sarcopenic patients incorporating HP ONS with HMB and resistance exercise is feasible and is associated with increased gait speed.

Purpose: Total neoadjuvant therapy (TNT) is becoming the standard of care for locally advanced rectal cancer. However, surgery is deferred for months after completion, which may lead to fibrosis and increased surgical difficulty. The aim of this study was to assess whether TNT (TNT-RAPIDO) is associated with increased difficulty of total mesorectal excision (TME) compared with long-course chemoradiotherapy (LCRT) and upfront surgery.Methods: Twelve laparoscopic videos of low anterior resection with TME for rectal cancer were prospectively collected from January 2020 to October 2021, with 4 videos in each arm. Seven colorectal surgeons assessed the videos independently, graded the difficulty of TME using a visual analog scale and attempted to identify which category the videos belonged to.Results: The median age was 67 years, and 10 patients were male. The median interval to surgery from radiotherapy was 13 weeks in the LCRT group and 24 weeks in the TNT-RAPIDO group. There was no significant difference in the visual analog scale for difficulty in TME between the 3 groups (LCRT, 3.2; TNT-RAPIDO, 4.6; upfront, 4.1; P=0.12). A subgroup analysis showed similar difficulty between groups (LCRT 3.2 vs. TNT-RAPIDO 4.6, P=0.05; TNT-RAPIDO 4.6 vs. upfront 4.1, P=0.54). During video assessments, surgeons correctly identified the prior treatment modality in 42% of the cases. TNT-RAPIDO videos had the highest recognition rate (71%), significantly outperforming both LCRT (29%) and upfront surgery (25%, P=0.01).Conclusion: TNT does not appear to increase the surgical difficulty of TME.

Background: Sarcopenia has been recognized as a determining factor in surgical outcomes and is associated with an increased risk of postoperative complications and readmission. Diagnosis is currently based on clinical guidelines, which includes assessment of skeletal muscle mass but not quality. Ultrasound has been proposed as a useful point-of-care diagnostic tool to assess muscle quality, but no validated cut-offs for sarcopenia have been reported. Using novel automated artificial intelligence (AI) software to interpret ultrasound images may assist in mitigating the operator-dependent nature of the modality. Our study aims to evaluate the fidelity of AI-aided ultrasound as a reliable and reproducible modality to assess muscle quality and diagnose sarcopenia in surgical patients. Methods: Thirty-six adult participants from an outpatient clinic were recruited for this prospective cohort study. Sarcopenia was diagnosed according to Asian Working Group for Sarcopenia (AWGS) 2019 guidelines. Ultrasonography of the rectus femoris muscle was performed, and images were analyzed by an AI software (MuscleSound® (Version 5.69.0)) to derive muscle parameters including intramuscular adipose tissue (IMAT) as a proxy of muscle quality. A receiver operative characteristic (ROC) curve was used to assess the predictive capability of IMAT and its derivatives, with area under the curve (AUC) as a measure of overall diagnostic accuracy. To evaluate consistency between ultrasound users of different experience, intra- and inter-rater reliability of muscle ultrasound parameters was analyzed in a separate cohort using intraclass correlation coefficients (ICC) and Bland–Altman plots. Results: The median age was 69.5 years (range: 26–87), and the prevalence of sarcopenia in the cohort was 30.6%. The ROC curve plotted with IMAT index (IMAT% divided by muscle area) yielded an AUC of 0.727 (95% CI: 0.551–0.904). An optimal cut-off point of 4.827%/cm² for IMAT index was determined with a Youden’s Index of 0.498. We also demonstrated that IMAT index has excellent intra-rater reliability (ICC = 0.938, CI: 0.905–0.961) and good inter-rater reliability (ICC = 0.776, CI: 0.627–0.866). In Bland–Altman plots, the limits of agreement were from −1.489 to 1.566 and −2.107 to 4.562, respectively. Discussion: IMAT index obtained via ultrasound has the potential to act as a point-of-care evaluation for sarcopenia screening and diagnosis, with good intra- and inter-rater reliability. The proposed IMAT index cut-off maximizes sensitivity for case finding, supporting its use as an easily implementable point-of-care test in the community for sarcopenia screening. Further research incorporating other ultrasound parameters of muscle quality may provide the basis for a more robust diagnostic tool to help predict surgical risk and outcomes.

Background: Multimodal analgesia is now widely practised to minimise postoperative opioid consumption while optimising pain control. The aim of this meta-analysis was to assess the analgesic efficacy of erector spinae plane block (ESPB) in patients undergoing laparoscopic abdominal surgeries. This will be determined by perioperative opioid consumption, subjective pain scores, and incidences of postoperative nausea and vomiting. Methods: The authors systemically searched electronic databases for randomised controlled trials (RCTs) published up to February 2023 comparing ESPB with other adjuvant analgesic techniques in laparoscopic abdominal surgeries. Nine randomised controlled trials encompassing 666 subjects were included in our study. Results: ESPB was shown to reduce postoperative opioid consumption [mean difference (MD) of −5.95 mg (95% CI: −8.86 to −3.04; PI ²=89%], intraoperative opioid consumption MD of −102.4 mcg (95% CI: −145.58 to −59.21; PI ²=39%, and incidence of nausea [RR 0.38 (95% CI: 0.25–0.60; PI ²=0%] and vomiting [RR 0.32 (95% CI: 0.17–0.63; P=0.0009); I ²=0%] in laparoscopic abdominal surgeries. Subgroup analysis on laparoscopic colorectal surgeries further showed reduction in postoperative pain scores MD of −0.68 (95% CI: −0.94 to −0.41); PI ²=0%]. Conclusions: This study concludes that ESPB is a valuable technique with proven efficacy to potentially promote faster postoperative recovery through optimising pain control while minimising opioid requirements.

Sarcopenia, which is characterized by progressive and generalized loss of skeletal muscle mass and strength, has been well described to be associated with numerous poor postoperative outcomes, such as increased perioperative mortality, postoperative sepsis, prolonged length of stay, increased cost of care, decreased functional outcome, and poorer oncological outcomes in cancer surgery. Multimodal prehabilitation, as a concept that involves boosting and optimizing the preoperative condition of a patient prior to the upcoming stressors of a surgical procedure, has the purported benefits of reversing the effects of sarcopenia, shortening hospitalization, improving the rate of return to bowel activity, reducing the costs of hospitalization, and improving quality of life. This review aims to present the current literature surrounding the concept of sarcopenia, its implications pertaining to colorectal cancer and surgery, a summary of studied multimodal prehabilitation interventions, and potential future advances in the management of sarcopenia.