Cheryl Xi-Zi Chong

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.

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.

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.