Efficacy of autologous platelet-rich plasma gel in patients with hard-to-heal diabetic foot ulcers: a multicentre study in Japan.

OBJECTIVE: To evaluate the healing outcome of a platelet-rich plasma (PRP) gel prepared using TKKT01 (a wound care device to prepare the PRP gel) in patients with hard-to-heal diabetic foot ulcers (DFUs) and who showed an inadequate response to ≥4 weeks of standard of care (SoC). METHOD: This open-label, single-arm, multicentre study was conducted in 15 centres in Japan. Eligible patients received PRP gel treatment twice a week for eight weeks, followed by a final evaluation after the completion of week 8 (day 57). The primary endpoint was the percentage of patients who achieved ≥50% reduction in wound radius at the final evaluation (achievement criterion, ≥60% of patients). Secondary endpoints included: wound area and volume reduction rates; time to possible wound closure by secondary intention; time to possible wound closure using a relatively simple procedure (e.g., skin graft and suture); and safety at the final evaluation. RESULTS: A total of 54 patients were included in the full analysis set, with 47 patients included in the per protocol set; the primary endpoint was met in 38/47 (80.9%) (95% confidence interval: 66.7-90.9%) patients who achieved ≥50% wound radius reduction at the final evaluation. High rates of wound area (72.8%) and volume (92.7%) reduction were observed at the final evaluation. The median time to possible wound closure by secondary intention and by use of a relatively simple procedure was 57 and 43 days, respectively. Complete wound closure at the final evaluation was achieved in 27 (57.4%) patients. No safety concerns were raised. CONCLUSION: In this study, the efficacy and safety of PRP gel treatment with TKKT01 in patients with hard-to-heal DFUs in Japan were confirmed by our findings. DECLARATION OF INTEREST: This study was funded by Rohto Pharmaceutical Co., Ltd., Japan. NO has been paid a consulting fee by Rohto Pharmaceutical Co., Ltd. KH is the Chief Medical Officer of Rohto Pharmaceutical. Co., Ltd. The other authors have no conflict of interest to declare.

Dramatic Wound Closing Effect of a Single Application of an iBTA-Induced Autologous Biosheet on Severe Diabetic Foot Ulcers Involving the Heel Area.

INTRODUCTION: Chronic wounds caused by diabetes or lower-extremity artery disease are intractable because the wound healing mechanism becomes ineffective due to the poor environment of the wound bed. Biosheets obtained using in-body tissue architecture (iBTA) are collagen-based membranous tissue created within the body and which autologously contain various growth factors and somatic stem cells including SSEA4-posituve cells. When applied to a wound, granulation formation can be promoted and epithelialization may even be achieved. Herein, we report our clinical treatment experience with seven cases of intractable diabetic foot ulcers. CASES: Seven patients, from 46 to 93 years old, had large foot ulcers including in the heel area, which were failing to heal with standard wound treatment. METHODS: Two or four Biosheet-forming molds were embedded subcutaneously in the chest or abdomen, and after 3 to 6 weeks, the molds were removed. Biosheets that formed inside the mold were obtained and applied directly to the wound surface. RESULTS: In all cases, there were no problems with the mold's embedding and removal procedures, and Biosheets were formed without any infection or inflammation during the embedding period. The Biosheets were simply applied to the wounds, and in all cases they adhered within one week, did not fall off, and became integrated with the wound surface. Complete wound closure was achieved within 8 weeks in two cases and within 5 months in two cases. One patient was lost due to infective endocarditis from septic colitis. One case required lower leg amputation due to wound recurrence, and one case achieved wound reduction and wound healing in approximately 9 months. CONCLUSIONS: Biosheets obtained via iBTA promoted wound healing and were extremely useful for intractable diabetic foot ulcers involving the heel area.

First-in-human results of an in-body tissue architecture-induced tissue-engineered vascular graft "Biotube" for application in distal bypass for chronic limb-threatening ischemia.

Small-diameter vascular substitutes remain necessary, especially in the absence of an available autologous vein. Using a completely autologous approach termed "in-body tissue architecture," a small-diameter, long, tissue-engineered vascular graft, a "Biotube," was developed. A below-the-knee distal bypass using the Biotube as a composite with expanded polytetrafluoroethylene grafts was performed to treat a patient with chronic limb-threatening ischemia without a venous graft available. The wound on the foot had completely healed 3 months after the bypass surgery, and limb salvage and walking without claudication were achieved. At the 1-year postoperative follow-up examination, duplex ultrasound scans demonstrated graft patency without thrombus or stenosis.

Pre-implantation evaluation of a small-diameter, long vascular graft (Biotube®) for below-knee bypass surgery in goats.

There are no small-diameter, long artificial vascular grafts for below-knee bypass surgery in chronic limb-threatening ischemia. We have developed tissue-engineered vascular grafts called "Biotubes®" using a completely autologous approach called in-body tissue architecture (iBTA). This study aimed at pre-implantation evaluation of Biotube and its in vivo preparation device, Biotube Maker, for use in below-knee bypass surgery. Forty nine makers were subcutaneously embedded into 17 goats for predetermined periods (1, 2, or 3 months). All makers produced Biotubes as designed without inflammation over all periods, with the exception of a few cases with minor defects (success rate: 94%). Small hole formation occurred in only a few cases. All Biotubes obtained had an inner diameter of 4 mm and a length of 51 to 52 cm with a wall thickness of 594 ± 97 µm. All Biotubes did not kink when completely bent under an internal pressure of 100 mmHg and did not leak without any deformation under a water pressure of 200 mmHg. Their burst strength was 2409 ± 473 mmHg, and suture retention strength was 1.75 ± 0.27 N, regardless of the embedding period, whereas tensile strength increased from 7.5 ± 1.3 N at 1 month to 9.7 ± 2.0 N at 3 months with the embedding period. The amount of water leakage from the needle holes prepared in the Biotube wall was approximately 1/7th of that in expanded polytetrafluoroethylene vascular grafts. The Biotubes could be easily connected to each other without cutting or anastomosis leaks. They could be stored for at least 1 year at room temperature. This study confirmed that even Biotubes formed 1 month after embedding of Biotube Makers had properties comparable to arteries.

Acute Phase Pilot Evaluation of Small Diameter Long iBTA Induced Vascular Graft "Biotube" in a Goat Model.

OBJECTIVE: There is a need for small diameter vascular substitutes in the absence of available autologous material. A small diameter, long tissue engineered vascular graft was developed using a completely autologous approach called "in body tissue architecture technology (iBTA)". The aim of this pilot study was to evaluate "Biotubes", iBTA induced autologous collagenous tubes, for their potential use as small diameter vascular bypass conduits. METHODS: Biotubes (internal diameter 4 mm, length 50 cm, wall thickness 0.85 mm) were prepared by subcutaneous embedding of plastic moulds (Biotube Maker) in three goats for approximately two months. Allogenic Biotubes (length 10 cm [n = 2], 15 cm [n = 2], 22 cm [n = 2]) were bypassed to both carotid arteries by end to side anastomosis with their ligation between the anastomoses in another three goats. Residual Biotubes were examined for their mechanical properties. After four weeks, the harvested Biotubes were evaluated histologically. RESULTS: All Biotubes had sufficient pressure resistance, approximately 3000 mmHg. Although wall thickening occurred at two proximal anastomosis sites, all six grafts were patent without luminal thrombus formation, stenosis, or aneurysm deformation throughout the implantation period. Endothelial cells covered both anastomosis sites almost completely, with partial covering in the central portion of the grafts. Furthermore, α smooth muscle actin positive cells infiltrated the middle layer along almost the entire graft length. CONCLUSION: This preliminary study showed that small diameter, long, tissue engineered Biotubes could function properly as arterial bypass conduits in a large animal for one month without any abnormal change in vascular shape. Thus, small diameter, long Biotubes are potentially viable conduits, which are biocompatible and labour non-intensive, and therefore, suitable for clinical practice. Additionally, Biotubes can start the regeneration process in a short period of time.

Identification of Risk Factors for Daptomycin-Associated Creatine Phosphokinase Elevation and Development of a Risk Prediction Model for Incidence Probability.

BACKGROUND: In this study, we investigated the risk factors for daptomycin-associated creatine phosphokinase (CPK) elevation and established a risk score for CPK elevation. METHODS: Patients who received daptomycin at our hospital were classified into the non-elevated or elevated CPK group based on their peak CPK levels during daptomycin therapy. Univariable and multivariable analyses were performed, and a risk score and prediction model for the incidence probability of CPK elevation were calculated based on logistic regression analysis. RESULTS: The non-elevated and elevated CPK groups included 181 and 17 patients, respectively. Logistic regression analysis revealed that concomitant statin use (odds ratio [OR], 4.45 [95% confidence interval {CI}, 1.40-14.47]; risk score 4), concomitant antihistamine use (OR, 5.66 [95% CI, 1.58-20.75]; risk score 4), and trough concentration (Cmin) between 20 and <30 µg/mL (OR, 14.48 [95% CI, 2.90-87.13]; risk score 5) and ≥30.0 µg/mL (OR, 24.64 [95% CI, 3.21-204.53]; risk score 5) were risk factors for daptomycin-associated CPK elevation. The predicted incidence probabilities of CPK elevation were <10% (low risk), 10%-<25% (moderate risk), and ≥25% (high risk) with total risk scores of ≤4, 5-6, and ≥8, respectively. The risk prediction model exhibited a good fit (area under the receiver operating characteristic curve, 0.85 [95% CI, .74-.95]). CONCLUSIONS: These results suggested that concomitant use of statins with antihistamines and Cmin ≥20 µg/mL were risk factors for daptomycin-associated CPK elevation. Our prediction model might aid in reducing the incidence of daptomycin-associated CPK elevation.

Population Pharmacokinetic Analysis and Dosing Optimization Based on Unbound Daptomycin Concentration and Cystatin C in Nonobese Elderly Patients with Hypoalbuminemia and Chronic Kidney Disease.

PURPOSE: This study evaluated the population pharmacokinetics of daptomycin in nonobese elderly patients with hypoalbuminemia and chronic kidney disease (CKD) using the glomerular filtration rate estimated from cystatin C (eGFRcys) and estimated its optimal dose. METHODS: We performed population pharmacokinetic analysis of the unbound concentrations of daptomycin. The probability of target attainment of 90% for achieving an area under the concentration-time curve of unbound daptomycin at steady state/ minimum inhibitory concentration ratio of ≥66.6 was stochastically simulated. RESULTS: In the population pharmacokinetic analysis of 25 patients aged ≥65 years, the two-compartment model using eGFRcys and age as covariates of clearance in central compartment of unbound daptomycin were optimal. The unbound fraction rate (fu) was 0.05-0.14. According to the Monte Carlo simulation, the optimal doses for patients with eGFRcys of 20-60 mL/min and aged 65-95 years were calculated as 200-500 mg q24h. CONCLUSION: These results suggest that establishing the dose using total concentrations may result in under- or overestimation caused by alterations in fu. The optimal dose for nonobese elderly patients with hypoalbuminemia and CKD depends on eGFRcys and age, and a standard dose may be insufficient for some patients.

NT5E Genetic Mutation Is a Rare But Important Cause of Intermittent Claudication and Chronic Limb-Threatening Ischemia.

BACKGROUND: NT5Egenetic mutations are known to result in calcification of joints and arteries (CALJA), and worldwide, 14 patients from 7 families have been reported.Methods and Results:A total of 5 patients from 2 independent families with CALJA were found in Japan. Of them, 3 complained of intermittent claudication (IC), and 1 suffered from bilateral chronic limb-threatening ischemia (CLTI). Whole-exome sequencing analysis revealed an identical mutation pattern (c.G3C on the exon 1 start codon) that was unique compared withNT5Emutations reported in other countries. CONCLUSIONS: Vascular specialists need to recognize CALJA as a rare cause of ischemic IC and CLTI.

A retrospective, longitudinal study to evaluate healing lower extremity wounds in patients with diabetes mellitus and ischemia using standard protocols of care and platelet-rich plasma gel in a Japanese wound care program.

Chronic wounds, especially in patients with diabetes mellitus (DM), are a major health challenge in Japan. The goal of wound care centers (WCCs) in Japan is to facilitate healing and prevent lower extremity amputations (LEAs) using standardized protocols of patient and wound care. The standard treatment algorithm includes a complete patient and wound assessment, history, physical exam, and a variety of diagnostic tests that determine the need for infection control intervention, revascularization, excision and debridement, growth factor/platelet rich plasma (PRP) gel therapy, skin graft/ flap, wound protection, and education. All patient and wound data are entered in a secure central database for all WCCs. To evaluate the outcomes of standard care regimens compared to the use of a topical PRP gel treatment in patients with a variety of complex wounds, a retrospective, longitudinal study was conducted. Wound outcomes from 39 patients with 40 chronic, nonhealing, lower extremity wounds were evaluated between two time periods: between first presentation at the WCC (T1) and after using standard topical treatments (T2) and between T2 and after using the PRP gel treatment (T3). Patient average age was 66.8 years (SD: 10.60) and mean wound duration was 99.7 days before treatment (SD: 107.73); and the majority of patients (85%) had DM. Wounds were classified as ischemic diabetic (n = 24), diabetic (n = 10), ischemic (n = 5), and pressure ulcer (n = 1). DFUs were Wagner III (77%) and lV (23%). Of those, 60% were in patients with arteriosclerotic obliterans (ASO). Infection (abscess, cellulitis, osteomyelitis, and/or gangrene) was present in all wounds and treated using debridement, antibiotic therapy, and surgery as deemed appropriate. During the first treatment period (T1 to T2) of 75.3 days, which included revascularization and/or debridement along with standard of care, none of the wounds healed and the average wound area, depth, and volume increased. Following topical PRP gel treatment, 83% of wounds healed within 145.2 days (T2 to T3) (P = 0.00002). Only one patient required an LEA. The results of this study suggest that good healing outcomes and a low amputation rate can be obtained with a protocol of supportive care (including revascularization procedures) and the PRP gel treatment. Prospective controlled studies comparing the use of this PRP gel to other advanced treatments are warranted.

Long-term results after Starr-Edwards mitral valve replacement in children aged 5 years or younger.

BACKGROUND: Mitral valve replacement with prosthetic valves in infants and children requires consideration of multiple variables. When we examined our late follow-up, the effect of the growth of the patient relative to the size of the prosthesis placed was the most important variable predicting late successful results. We reviewed our experience with mitral valve replacement using the Starr-Edwards ball valve in children aged 5 years or younger, focusing on the effect of valve prosthesis-patient mismatch on the long-term results in the growing patient. METHODS: From August 1974 to June 1986, 8 patients aged 5 years or younger underwent mitral valve replacements using the Starr-Edwards prosthesis size OM in 3 patients and 1M in 5 patients. Model 6320 was used in 1 patient and Model 6120 in the remaining 7 patients. RESULTS: Follow-up was 100% from 15 to 27 years (mean, 20 years). No valve-related complications of thromboembolism, anticoagulant-related hemorrhage, or prosthetic valve endocarditis were seen. All patients normally developed to adult size. The range of the valve area index of the 3 patients who received the smaller Starr-Edwards valve (size OM) was 0.97 to 1.24 cm2/m2. Although this size valve was adequate for patient growth to adolescence, in each case valve replacement with a larger valve was required. CONCLUSIONS: Our long-term review of Starr-Edwards ball valve mitral valve replacement in children aged 5 years or younger shows that the Starr-Edwards ball valve (Models 6320 [1 patient] and 6120 [7 patients]) showed excellent durability, no thromboembolism, and no anticoagulant-related complications. Size OM valves required replacement for hemodynamic reasons because of patient growth; larger size 1M valves remained hemodynamically satisfactory in spite of patient growth.