Postoperative outcomes after prehabilitation for colorectal cancer patients undergoing surgery: a systematic review and meta-analysis of randomized and nonrandomized studies.

PURPOSE: Prehabilitation (PH) is purported to improve patients' preoperative functional status. This systematic review and meta-analysis sought to compare short-term postoperative outcomes between patients who underwent a protocolized PH program and the existing standard of care among colorectal cancer patients awaiting surgery. METHODS: A search in MEDLINE/PubMed, the Cochrane Library, Embase, Scopus, and CINAHL was conducted to identify relevant articles. Repetitive and exhaustive combinations of MeSH search terms ("prehabilitation," "colorectal cancer," "colon cancer," and "rectal cancer") were used to identify randomized and nonrandomized studies comparing PH versus standard of care for colorectal cancer patients awaiting surgery. The primary outcomes included postoperative morbidity, length of hospital stay, and readmission rates. RESULTS: Seven studies including 1,042 colorectal cancer patients (PH, 382) were included. No significant differences were found in intraoperative outcomes. The postoperative complication rates were comparable between groups (Clavien-Dindo grades I and II: risk ratio, 0.82; 95% confidence interval, 0.62-1.07; P=0.15; Clavien-Dindo grades ≥III: risk ratio, 1.02; 95% confidence interval, 0.72-1.44; P=0.92). There were also no significant differences in length of hospital stay (P=0.21) or the risk of 30-day readmission (P=0.68). CONCLUSION: Although PH does not appear to improve short-term postoperative outcomes following colorectal cancer surgery, the quality of evidence is impaired by the limited trials and heterogeneity. Thus, further large-scale trials are warranted to draw definitive conclusions and establish the long-term effects of PH.

Pericapsular nerve group (PENG) block for early pain management of elderly patients with hip fracture: a single-center double-blind randomized controlled trial.

BACKGROUND: The pericapsular nerve group block (PENG) is a novel technique that blocks the articular branches of the hip joint. This study aimed to compare its effectiveness to a sham block in elderly patients with hip fractures. METHOD: A randomized double-blind controlled trial was conducted in elderly patients with intertrochanteric and neck of femur fractures. Patients were randomized to receive either PENG block or a sham block. Postblock, systemic analgesia was titrated using a standardized protocol of acetaminophen, oral morphine or patient-controlled analgesia. The primary outcome was the dynamic pain score (Numerical Rating Scale 0-10) at 30 min postblock. Secondary outcomes included pain scores at multiple other time points and 24-hour opioid consumption. RESULTS: 60 patients were randomized and 57 completed the trial (PENG n=28, control n=29). Patients in PENG group had significantly lower dynamic pain scores at 30 min compared with control group (median (IQR) 3 (0.5-5) vs 5 (3-10), p<0.01). For the secondary outcomes, dynamic pain scores were lower in PENG group at 1 hour (median (IQR) 2 (1-3.25) vs 5 (3-8), p<0.01) and 3 hours postblock (median (IQR) 2 (0-5) vs 5 (2-8), p<0.05). Patients in PENG group had lower 24-hour opioid consumption (median (IQR) oral morphine equivalent dose 10 (0-15) vs 15 (10-30) mg, p<0.05). CONCLUSION: PENG block provided effective analgesia for acute traumatic pain following hip fracture. Further studies are required to validate the superiority of PENG blocks over other regional techniques. TRIAL REGISTRATION NUMBER: NCT04996979.

Transforming the perioperative medicine care model: The Singapore experience.

More than 300 million surgeries are performed worldwide annually. Established perioperative centres in the UK, USA and Australia have demonstrated the impact of improving perioperative care in reducing costs, increasing patient satisfaction and improving population health. Likewise, the surgical burden of care in Asia is increasing, but with sociocultural, economic and epigenetic differences compared to the west. As Singapore's largest hospital, the Singapore General Hospital pre-admission perioperative clinic sees about 20,000 patients annually. We aim to illustrate Singapore General Hospital's perioperative model of care to contribute to the paucity of literature describing perioperative programme implementation within Asia, and to encourage the cross-sharing of perioperative practices internationally. Our perioperative framework navigates risk assessment, risk counselling, and mitigation of health, medical and functional risks to better patients' perioperative outcomes and population health. We have implemented evidence-based pathways for common conditions such as anaemia and malnutrition, including a multidisciplinary programme for the elderly to tackle frailty and reduce length of stay. We describe how we have enhanced local risk profiling with the Combined Assessment of Risk Encountered in Surgery surgical risk calculator derived locally using a gradient boosting machine learning model. Finally, we report clinical outcomes of these interventions and discuss further challenges and new initiatives at each tier of our perioperative model. Our perioperative care model provides a framework that other centres can adopt to promote value-driven care, while catering for differences in the Asian population, thereby promoting evidence-based improvements in the area of perioperative medicine.

Preparation and consideration for establishment of an isolation maternity unit in a tertiary hospital during COVID-19 pandemic.

The SARS-CoV-2 pandemic is rapidly evolving and remains a major health challenge worldwide. With an increase in pregnant women with COVID-19 infection, we recognized an urgent need to set up a multidisciplinary taskforce to provide safe and holistic care for this group of women. In this review of practice in a tertiary hospital in Singapore, we discuss the key considerations in setting up an isolation maternity unit and our strategies for peripartum and postpartum care. Through teleconsultation, we involve these women and their families in the discussion of timing and mode of birth, disposition of babies after birth and safety of breastfeeding to enable them to make informed decisions and individualize their care.

Developing a Simpler Prognosticating Tool: Comparing the Combined Assessment of Risk Encountered in Surgery Score with Deyo-Charlson Comorbidity Index and The American Society of Anesthesiologists Physical Status Score in Predicting 2 years Mortality after Hip Fracture Surgery.

Background: The use of risk stratification tools in identifying high-risk hip fracture patients plays an important role during treatment. The aim of this study was to compare our locally derived Combined Assessment of Risk Encountered in Surgery (CARES) score with the the American Society of Anesthesiologists physical status (ASA-PS) score and the Deyo-Charlson Comorbidity Index (D-CCI) in predicting 2-year mortality after hip fracture surgery. Methods and Material: A retrospective study was conducted on surgically treated hip fracture patients in a large tertiary hospital from Jan 2013 through Dec 2015. Age, gender, time to surgery, ASA-PS score, D-CCI, and CARES score were obtained. Univariate and multivariable logistic regression analyses were used to assess statistical significance of scores and risk factors, and area under the receiver operating characteristic (ROC) curve (AUC) was used to compare ASA-PS, D-CCI, and CARES as predictors of mortality at 2 years. Results: 763 surgically treated hip fracture patients were included in this study. The 2-year mortality rate was 13.1% (n = 100), and the mean ± SD CARES score of surviving and demised patients was 21.2 ± 5.98 and 25.9 ± 5.59, respectively. Using AUC, CARES was shown to be a better predictor of 2-year mortality than ASA-PS, but we found no statistical difference between CARES and D-CCI. A CARES score of 23, attributable primarily to pre-surgical morbidities and poor health of the patient, was identified as the statistical threshold for "high" risk of 2-year mortality. Conclusion: The CARES score is a viable risk predictor for 2-year mortality following hip fracture surgery and is comparable to the D-CCI in predictive capability. Our results support the use of a simpler yet clinically relevant CARES in prognosticating mortality following hip fracture surgery, particularly when information on the pre-existing comorbidities of the patient is not immediately available.

Preoperative Single-Dose Intravenous Iron Formulation to Reduce Postsurgical Complications in Patients Undergoing Major Abdominal Surgery: A Randomized Control Trial Feasibility Study (PIRCAS Trial Pilot).

Background Preoperative anemia is associated with an increased need for blood transfusion, complications, and prolonged hospital stay. Iron deficiency anemia (IDA) may be treated with oral or intravenous (IV) iron. IV iron repletes iron stores more rapidly. Its impact on perioperative blood transfusion, postoperative complications, patients' recovery, and long-term quality of life is unclear. Newer agents, such as ferric carboxymaltose (FCM), are costly but have higher maximum approved doses and a very low incidence of anaphylactic-type reactions. This study aims to explore the feasibility of a randomized control trial to compare the preoperative treatment of IDA with IV FCM versus oral ferrous fumarate, in patients undergoing elective major abdominal surgery. Experimental design This is an open-label pilot randomized controlled trial. A total of 30 adults with IDA scheduled for elective major abdominal surgery were recruited for the study. They were randomized into two groups to receive either oral iron or IV FCM. Primary outcomes are defined as the time from enrollment to study drug administration, recruitment rate, and follow-up rate up to three months. Secondary outcomes are hemoglobin rise from recruitment to surgery, perioperative blood transfusion, postoperative complications, EQ-5D-3L scores at baseline, and three months and adverse events related to IV FCM therapy. Results All patients received study drugs within five days of enrollment; 30 patients were recruited within four months, 15 patients in each group. Two in each group were withdrawn for surgery postponement. All patients were followed up for three months and there was no crossover of patients. Per protocol, analysis was performed. No severe adverse events related to IV FCM therapy occurred. Both groups had similar baseline characteristics, similar hemoglobin rise from enrollment to the day of surgery [0.2 (+1.6) g/dL in the FCM group and 0.8 (+0.7) g/dL in the Oral Iron group, p=0.3] and similar mean units of perioperative blood transfused (recruitment to discharge) per patient [1.3 (+ 2.1) in the FCM group and 0.9 (+1.3) in the Oral Iron group, p=0.6]. Postoperatively, there was a similar hospital length of stay [11.5 (+13.6 days) in the FCM group and 9.0 (+9.8 days) in the Oral Iron group, p=0.6]; there were similar postoperative complications as reflected by the average Comprehensive Complication Index [12.8 (+19.6) in the FCM group and 22.6 (+30.7) in the Oral Iron group, p=0.3]; similar postoperative health-related quality of life as reflected by mean EQ-5D-3L scores at one month [70.4 (+21.8) in the FCM group and 84.5 (+12.1) in the Oral Iron group] and three months [80.0 (+18.4) in the FCM group and 85.9 (+10.7) in the Oral Iron group]. Conclusions A full-scale randomized controlled trial to evaluate the effectiveness of preoperative IV FCM compared to oral iron in patients with IDA undergoing major abdominal surgery is feasible.

Association of Multimorbidity With Frailty in Older Adults for Elective Non-Cardiac Surgery.

Introduction Frailty is associated with adverse surgical outcomes. While existing studies describe the prevalence of multimorbidity and frailty in the community, the surgical population may have more severe disease and significant surgical stress. This study aims to describe the distribution of frailty and multimorbidity in the older surgical population and examine if specific comorbidities are more strongly associated with frailty. Methods This is a single-centre retrospective cohort study using an electronic database in the preoperative evaluation clinic, conducted in Singapore General Hospital, Singapore. All patients above 70 years old going for elective non-cardiac surgery were included. Demographics and comorbidities were analysed for their association with frailty according to the Edmonton Frail Scale. Results A total of 1396 out of 1398 patients were analyzed. The overall incidence of frailty was 27.8% and multimorbidity was 63.4%. Factors independently associated with frailty were age (adjusted Odds Ratio [aOR] = 1.07), female gender (aOR = 1.67), type 2 diabetes mellitus (aOR = 1.69), chronic kidney disease (aOR = 1.47), end-stage renal failure (aOR = 3.58), history of cerebrovascular accident or transient ischemic attack (aOR = 1.87), moderate anaemia (aOR = 2.11), dementia (aOR = 6.38), depression (aOR = 3.82), and peptic ulcer disease (aOR = 1.98). The presence of multi-morbidity was significantly associated with frailty, with overall increasing strength of association. Conclusion As the number of comorbidities increases, the odds of frailty increase. Only a small proportion of those with multimorbidity accumulate enough biological deficits to develop frailty, putting them at higher risk than with solely multimorbidity or frailty. Dementia and depression are comorbidities with strong associations that have yet to see coordinated interventional efforts in the preoperative setting.

A Newly Proposed HbA1C-Hemoglobin Ratio - A Better Predictor of Outcomes in Cardiac Surgery When Compared to HbA1C and Anemia Alone.

HbA1C's predictive value for postoperative complications in cardiac surgery has been mixed. Studies did not account for HbA1C being over-read in anemic patients. This study proposes a novel way of using a ratio of HbA1C over hemoglobin (HH ratio). Retrospective recruitment of patients undergoing cardiac surgery was done with ethics approval. The primary objective of our study is to look for the correlation of HH ratio with 90-day (short-term) and 1-year (long-term) mortality. The secondary objective is to investigate its association with other adverse events. Statistical analysis was done using multivariable regressions and Cox proportional hazard models. Of the 974 patients recruited, 618 had a HH Ratio<0.5, 284 between 0.5-0.7 and 72 had the ratio >0.7. HH ratio of 0.5-0.7 and >0.7 was associated with 90-day mortality (HR 5.12, P = 0.033 and HR 7.25, P= 0.048 respectively) and 1-year mortality (HR 4.53, P = 0.028 and HR 9.20, P = 0.022 respectively). The higher HH ratio groups were also associated with increased length of stay (hours) in the intensive care unit (P < 0.001) and renal complications (P < 0.001). Our study showed a positive association of HH ratio with 90-day and 1-year mortality and postoperative adverse outcomes in patients undergoing cardiac surgery. The HH ratio has the potential to be a new perioperative target.

Assessment of predictive validity and feasibility of Edmonton Frail Scale in identifying postoperative complications among elderly patients: a prospective observational study.

Frailty is defined as diminished physiological reserve predisposing one to adverse outcomes when exposed to stressors. Currently, there is no standardized Frail assessment tool used perioperatively. Edmonton Frail Scale (EFS), which is validated for use by non-geriatricians and in selected surgical populations, is a candidate for this role. However, little evaluation of its use has been carried out in the Asian populations so far. This is a prospective observational study done among patients aged 70 years and above attended Preoperative Assessment Clinic (PAC) in Singapore General Hospital prior to major abdominal surgery from December 2017 to September 2018. The Comprehensive Complication Index (CCI) and Postoperative Morbidity Survey (POMS) were used to assess their postoperative morbidity respectively. Patient's acceptability of EFS was measured using the QQ-10 questionnaire and the inter-rater reliability of EFS was assessed by Kappa statistics and Bland Altman plot. The primary aim of this study is to assess if frailty measured by EFS is predictive of postoperative complications in elderly patients undergoing elective major abdominal surgery. We also aim to assess the feasibility of implementing EFS as a standard tool in the outpatient preoperative assessment clinic setting. EFS score was found to be a significant predictor of postoperative morbidity. (OR 1.35, p < 0.001) Each point increase in EFS score was associated with a 3 point increase in CCI score. (Coefficient b 2.944, p < 0.001) EFS score more than 4 has a fair predictability of both early and 30-day postoperative complications. Feasibility study demonstrated an overall acceptance of the EFS among our patients with good inter-rater agreement.

Serum albumin level predicts survival after surgical treatment of metastatic femur fractures: a retrospective study.

BACKGROUND: Surgical treatment for metastatic pathological femur fractures is associated with high mortality. Correct estimation of prognosis helps in determining the palliative value of surgical treatment and informs surgical decision. This study evaluates the risk factors for mortality in these patients who were surgically treated. METHODS: This is a retrospective study of 112 patients with surgical treatment of metastatic pathological femur fractures. Risk factors evaluated included age, ASA status, Charlson comorbidity index, preoperative serum albumin and haemoglobin, primary tumour site, presence of visceral metastases, presence of spinal metastases, time from diagnosis of cancer to occurrence of pathological fracture, type of surgical procedure performed, lesion and whether treatment was received for an actual or impending fracture. A Cox regression model was used to determine if these factors were independent significant factors for survival. RESULTS: Mortality at 2 years after surgical treatment of metastatic femoral fractures was 86%. Cox regression analysis of risk factors revealed that preoperative serum albumin and type primary tumour were independent risk factors for mortality. Presence of visceral metastases was strongly correlated to serum albumin levels. CONCLUSION: Preoperative serum albumin level and primary tumour site are independent risk factors of survival in patients treated for pathological femur fractures. Serum albumin level may be used as a prognostic tool to guide treatment in this cohort of patients with high mortality rates.

Sub-confluent culture of human mesenchymal stromal cells on biodegradable polycaprolactone microcarriers enhances bone healing of rat calvarial defect.

In the current emerging trend of using human mesenchymal stromal cell (MSCs) for cell therapy, large quantities of cells are needed for clinical testing. Current methods of culturing cells, using tissue culture flasks or cell multilayer vessels, are proving to be ineffective in terms of cost, space and manpower. Therefore, alternatives such as large-scale industrialized production of MSCs in stirred tank bioreactors using microcarriers (MCs) are needed. Moreover, the development of biodegradable MCs for MSC expansion can streamline the bioprocess by eliminating the need for enzymatic cell harvesting and scaffold seeding for bone-healing therapies. Our previous studies described a process of making regulated density (1.06 g/cm3) porous polycaprolactone biodegradable MCs Light Polycarprolactone (LPCL) (MCs), which were used for expanding MSCs from various sources in stirred suspension culture. Here, we use human early MSCs (heMSCs) expanded on LPCL MCs for evaluation of their osteogenic differentiation potential in vitro as well as their use in vivo calvarial defect treatment in a rat model. In summary, (i) in vitro data show that LPCL MCs can be used to efficiently expand heMSCs in stirred cultures while maintaining surface marker expression; (ii) LPCL MCs can be used as scaffolds for cell transfer for transplantation in vivo; (iii) 50% sub-confluency, mid-logarithmic phase, on LPCL MCs (50% confluent) exhibited higher secretion levels of six cytokines (interleukin [IL]-6, IL-8, Vascular endothelial growth factor (VEGF), Monocyte Chemoattractant Protein-1 (MCP-1), growth-regulated oncogene-α (GRO-α) and stromal cell-derived factor-1α (SDF-1α)) as compared with 100% confluent, stationary phase cultures (100% confluent); (iv) these 50% confluent cultures demonstrated better in vitro osteogenic differentiation capacity as compared with 100% confluent cultures (higher levels of calcium deposition and at earlier stage); the improved bone differentiation capacity of these 50% confluent cultures was also demonstrated at the molecular level by higher expression of early osteoblast genes Runt-related transcription factor 2 (RUNX2), Alkaline phosphatase (ALP), collagen type I, osterix and osteocalcin); and (v) in vivo implantation of biodegradable LPCL MCs covered with 50% heMSCs into rats with calvarial defect demonstrated significantly better bone formation as compared with heMSCs obtained from monolayer cultures (5.1 ± 1.6 mm3 versus 1.3 ± 0.7 mm3). Moreover, the LPCL MCs covered with 50% heMSCs supported better in vivo bone formation compared with 100% confluent culture (2.1 ± 1.3 mm3). Taken together, our study highlights the potential of implanting 50% confluent MSCs propagated on LPCL MCs as optimal for bone regeneration. This methodology allows for the production of large numbers of MSCs in a three-dimensional (3D) stirred reactor, while supporting improved bone healing and eliminating the need for a 3D matrix support scaffold, as traditionally used in bone-healing treatments.

Protocol for a single-centre prospective observational study of postoperative delirium following total joint arthroplasties among South East Asians.

INTRODUCTION: Postoperative delirium is a serious and common complication in older adults following total joint arthroplasties (TJA). It is associated with increased risk of postoperative complications, mortality, length of hospital stay and postdischarge institutionalisation. Thus, it has a negative impact on the health-related quality of life of the patient and poses a large economic burden. This study aims to characterise the incidence of postoperative delirium following TJA in the South East Asian population and investigate any risk factors or associated outcomes. METHODS AND ANALYSIS: This is a single-centre prospective observational study recruiting patients between 65 and 90 years old undergoing elective total knee arthroplasty or total hip arthroplasty. Exclusion criteria included patients with clinically diagnosed dementia. Preoperative and intraoperative data will be obtained prospectively. The primary outcome will be the presence of postoperative delirium assessed using the Confusion Assessment Method on postoperative days 1, 2 and 3 and day of discharge. Other secondary outcomes assessed postoperatively will include hospital outcomes, pain at rest, knee and hip function, health-related quality of life and Postoperative Morbidity Survey-defined morbidity. Data will be analysed to calculate the incidence of postoperative delirium. Potential risk factors and any associated outcomes of postoperative delirium will also be determined. ETHICS AND DISSEMINATION: This study has been approved by the Singapore General Hospital Institutional Review Board (SGH IRB) (CIRB Ref: 2017/2467) and is registered on the ClinicalTrials.gov registry (Identified: NCT03260218). An informed consent form will be signed by all participants before recruitment and translators will be made available to non-English-speaking participants. The results of this study will be presented at international conferences and submitted to a peer-reviewed journal. The data collected will also be made available in a public data repository. TRIAL REGISTRATION NUMBER: NCT03260218.

The use of computerized physician order entry with clinical decision support reduces practice variance in ordering preoperative investigations: A retrospective cohort study.

BACKGROUND AND GOAL OF STUDY: Over-ordering of routine preoperative investigations is prevalent. Adherence to institutional guidelines differs among physicians. Our institution integrated a Clinical Decision Support (CDS) model into our hospital's Computerized Physician Ordering Entry (CPOE) system to guide physician orders. We investigate if the implementation of CDS into CPOE increases physician adherence to our institutional guidelines. METHODS: A retrospective cohort study in a tertiary academic hospital over 18 months. The CDS model incorporated into the hospital's CPOE system prompts preoperative investigations based on the patient's age, gender, American Society of Anesthesiologists (ASA) score and complexity of the surgery when physicians use the Electronic Admission Form (EAF). These investigations include: Full Blood Count (FBC), Chest Radiography (CXR), Coagulation Panel (CP), Renal Panel (RP) and Electrocardiogram (ECG). Orders are 'concordant' if they followed guidelines; 'over' if they were not required by guidelines, and 'under' if they were required by guidelines but not ordered. RESULTS AND DISCUSSION: 11,792 patients - 7977 patients in the pre-implementation group, and 3815 patients in the post-implementation group. After implementation of CDS, overall guideline-concordant ordering rate increased by 3.9%, over orders decreased by 0.6% and under-orders decreased by 3.3% (P<0.001). CP showed the greatest increase in concordant orders by 12.0% and greatest decrease in under-orders by 11.1%. RP, ECG and CXR also showed modest increases in concordance rate. No significant change in ordering of FBC was found, due to the high pre-implementation concordance frequency of 96.3%. ECG and CXR have the lowest rates of concordant orders and highest rates of 'over' orders in both groups. Concordant orders were lowest in ASA 1 patients, and better in patients with higher ASA. Concordant orders across all ASA scores improved significantly after CDS was implemented. CONCLUSION: Implementation of CDS model into the CPOE system has improved physician adherence to guidelines for certain preoperative investigations.

Biodegradable poly-ε-caprolactone microcarriers for efficient production of human mesenchymal stromal cells and secreted cytokines in batch and fed-batch bioreactors.

Large numbers of human mesenchymal stromal cells (MSCs) used for a variety of applications in tissue engineering and cell therapy can be generated by scalable expansion in a bioreactor using microcarriers (MCs) systems. However, the enzymatic digestion process needed to detach cells from the growth surface can affect cell viability and potentially the potency and differentiation efficiency. Thus, the main aim of our study was to develop biocompatible and biodegradable MCs that can support high MSC yields while maintaining their differentiation capability and potency. After cell expansion, the cells that covered MCs can be directly implanted in vivo without the need for cell harvesting or use of scaffold. Poly-ε-caprolactone (PCL) is known as a biocompatible and biodegradable material. However, it cannot be used for generation of MCs because its high density (1.14 g/cm3) would exclude its applicability for suspension MCs in stirred reactors. In this article, we describe expansion and potency of MSCs propagated on low-density (1.06 g/cm3) porous PCL MCs coated with extracellular matrices (LPCLs) in suspended stirred reactors. Using these LPCLs, cell yields of about 4 × 104 cells/cm2 and 7- to 10-fold increases were obtained using four different MSC lines (bone marrow, cord blood, fetal and Wharton's jelly). These yields were comparable with those obtained using non-degradable MCs (Cytodex 3) and higher than two-dimensional monolayer (MNL) cultures. A fed-batch process, which demonstrated faster cell expansion (4.5 × 104 cells/cm2 in 5 days as compared with 7 days in batch culture) and about 70% reduction in growth media usage, was developed and scaled up from 100-mL spinner flask to 1-L controlled bioreactor. Surface marker expression, trilineage differentiation and clonogenic potential of the MSCs expanded on LPCL were not affected. Cytokine secretion kinetics, which occurred mostly during late logarithmic phase, was usually comparable with that obtained in Cytodex 3 cultures and higher than MNL cultures. In conclusion, biodegradable LPCL can be used to efficiently expand a variety of MSC lines in stirred scalable reactors in a cost-effective manner while maintaining surface markers expression, differentiation capability and high levels of cytokine secretion. This study is the first step in testing these cell-biodegradable porous MC aggregates for tissue engineering and cell therapy, such as bone and cartilage regeneration, or wound healing.

Biodegradable ECM-coated PCL microcarriers support scalable human early MSC expansion and in vivo bone formation.

BACKGROUND AIMS: Human mesenchymal stromal cells or marrow stromal cells (MSCs) are of great interest for bone healing due to their multi-potency and trophic effects. However, traditional MSC expansion methods using 2-dimensional monolayer (MNL) flasks or cell stacks are limited by labor-intensive handling, lack of scalability, the need for enzymatic cell harvesting and the need for attachment to a scaffold before in vivo delivery. Here, we present a biodegradable microcarrier and MSC bioprocessing system that may overcome the abovementioned challenges. METHODS: We cultured human early MSCs (heMSCs) on biodegradable polycaprolactone microcarriers (PCL MCs) coated with extracellular matrix (ECM) and evaluated the in vitro osteogenic differentiation and in vivo bone formation capacity of ECM-coated PCL MC-bound heMSCs compared with conventional MNL-cultured cells. RESULTS: We found that heMSCs proliferate well on PCL MCs coated with a fibronectin, poly-l-lysine, and fibronectin (FN+PLL+FN) coating (cPCL MCs). During in vitro osteogenic induction, heMSCs cultured on cPCL MCs displayed a 68% increase in specific calcium deposition compared with cultures on MNL. In a mouse ectopic mineralization model, bone mass was equivalent for MNL-expanded and cPCL MC-bound heMSC implants but higher in both cases when compared with cell-free cPCL MC implants at 16 weeks post-implantation. In summary, compared with MNL cultures, biodegradable MC MSC cultures provide the benefits of large-scale expansion of cells and can be delivered in vivo, thereby eliminating the need for cell harvesting and use of scaffolds for cell delivery. These results highlight the promise of delivering heMSCs cultured on cPCL MCs for bone applications.

Enhanced in vitro osteogenic differentiation of human fetal MSCs attached to 3D microcarriers versus harvested from 2D monolayers.

BACKGROUND: Mesenchymal stem cells (MSCs) are of great interest in bone regenerative medicine due to their osteogenic potential and trophic effects. However, challenges to large-scale production of MSCs can hinder the translation of MSC therapies. 3D Microcarrier (MC)-based MSC culture presents a scalable and cost-effective alternative to conventional methods of expansion in 2D monolayers. Furthermore, biodegradable MCs may allow for MC-bound MSC delivery without enzymatic harvest for selected applications such as bone healing. However, the effects of cell expansion on microcarriers and enzymatic cell harvest on MSC phenotype and osteogenic differential potential are not well understood. In this study, we characterized human fetal MSCs (hfMSCs) after expansion in 3D microcarrier spinner or 2D monolayer cultures. Following expansion, we compared osteogenic differentiation of cultures seeded with 3D MC-harvested, 3D MC-bound and conventional 2D monolayer (MNL)-harvested cells when cultured in osteogenic induction media on collagen-coated plates. RESULTS: Fetal MSCs expanded on both 3D agitated Microcarriers (MC) and 2D Plastic static monolayer (MNL) cultures express high levels of MSC surface markers. MC-harvested hfMSCs displayed higher expression of early osteogenic genes but slower mineralization kinetics compared to MNL-harvested MSCs during osteogenic induction. However, in the comparison between MC-bound and MC-harvested hfMSCs, osteogenic genes were upregulated and mineralization kinetics was accelerated in the former condition. Importantly, 3D MC-bound hfMSCs expressed higher levels of osteogenic genes and displayed either higher or equivalent levels of mineralization, depending on the cell line, compared to the classical monolayer cultures use in the literature (MNL-harvested hfMSCs). CONCLUSION: Beyond the processing and scalability advantages of the microcarrier culture, hfMSCs attached to MCs undergo robust osteogenic differentiation and mineralization compared to enzymatically harvested cells. Thus biodegradable/biocompatible MCs which can potentially be used for cell expansion as well as a scaffold for direct in vivo delivery of cells may have advantages over the current methods of monolayer-expansion and delivery post-harvest for bone regeneration applications.

Epidemiology of diabetic foot problems and predictive factors for limb loss.

OBJECTIVES: The aim of this study was to evaluate the epidemiology of diabetic foot problems (DFP) and predictive factors for major amputations (below- and above-knee). METHODS: This is a prospective study of 202 patients treated in National University Hospital (NUH) during the period of January 2005 to May 2006. A protocol was designed for documentation including patient profile, type of DFP, presence of risk factors, comorbidities and complications, clinical presentation, investigations, treatment given, and final outcome. The predictors for limb loss were determined using univariate and stepwise logistic regression analysis. RESULTS: One hundred ninety-two patients had Type 2 diabetes. Mean age of cohort was 60 years, with male to female ratio of 1:1. Incidence of DFP was significantly higher in Malays (P=.0015) and Indians (P=.036) and significantly lower in Chinese (P<.05). Of patients, 72.8% had poor endocrine control (GHb level >7%), and 42.1% of patients had sensory neuropathy based on 5.07 Semmes-Weinstein Monofilament test. Common DFP included gangrene (31.7%), infection (abscess, osteomyelitis) (28.7%), ulcer (27.7%), cellulitis (6.4%), necrotizing fasciitis (3.5%) and Charcot's osteoarthropathy (2.0%). Surgery was performed in 74.8% of patients and major amputation in 27.2% of patients (below-knee in 20.3% and above-knee in 6.9%). CONCLUSIONS: This is the first detailed prospective study evaluating predictive factors for major amputations in patients with DFP. Significant univariate predictive factors for limb loss were age above 60 years, stroke, ischaemic heart disease, nephropathy, peripheral vascular disease (PVD), sensory neuropathy, glycosylated haemoglobin level, Ankle Brachial Index (ABI) <0.8, gangrene, infection, and pathogens such as methicillin-resistant Streptococcus aureus (MRSA) and Staphylococcus aereus. Upon stepwise logistic regression analysis, only PVD and infection were significant.

Assessment of sensory neuropathy in diabetic patients without diabetic foot problems.

OBJECTIVES: To study the incidence and extent of peripheral sensory neuropathy in diabetic patients without diabetic foot problems (DFPs) with <5, 5-10 and >10 years duration of diabetes using three different modalities of testing: Pin-Prick Testing, 5.07 Semmes-Weinstein Monofilament Testing (SWMT) and Rapid-Current Perception Threshold (R-CPT) measurements using the Neurometer. METHODS: Our study population consisted of 60 patients (120 feet) treated for diabetes mellitus in the Division of Endocrinology at the National University Hospital. No patient had any DFPs. Twenty-two, 21 and 17 patients had duration of diabetes of <5, 5-10 and >10 years, respectively. All patients were tested for sensory neuropathy using Pin-Prick Testing using a standardized protocol, SWMT and the Neurometer. RESULTS: There was a significantly higher incidence of sensory neuropathy detected by both the Pin-Prick Test and the Neurometer as compared to the SWMT. Also, in all three modalities, there was a significant increase in incidence of sensory neuropathy detected in diabetics with >5 years duration of diabetes. In addition, the Pin-Prick Test showed an increase in extent of sensory neuropathy with a longer duration of diabetes. CONCLUSIONS: The Pin-Prick Test was found to be a simple, cheap and useful diagnostic tool for detection of sensory neuropathy in diabetics without DFPs. In addition, it could accurately delineate the extent of neuropathy in the lower limb - additional useful information not obtainable with SWMT or Neurometer. Even for patients with <5 years duration of diabetes, the incidence of sensory neuropathy detected was considerable. The incidence of neuropathy detected continued to increase with length of duration of diabetes. Hence, we recommend screening of patients for neuropathy as soon as they are diagnosed with diabetes.