Asymmetric Implant Design for Posterolateral Overhang of the Femoral Component in Total Knee Arthroplasty: A Retrospective Computed Tomography-Based Study.

Introduction During total knee arthroplasty (TKA), also referred to as total knee replacement (TKR), patients may experience pain in the posterolateral knee. One possible cause is the impingement between the popliteus tendon and the femoral components. The purpose of this study was to analyze the posterolateral overhang of the femoral component using 3D template software. Methods Preoperative CT scan images of 50 knees (11 males and 39 females) with osteoarthritis of grade 2 or lower according to the Kellgren-Lawrence classification were analyzed. The mean age of the subjects was 73.8±7.6 years (range 52-84 years). The Athena (Soft Cube Co., Ltd., Osaka, Japan) knee 3D image-matching software was used for the analysis. The positions of the two femoral components (symmetrical and asymmetrical) were simulated. In the coronal plane, the component overhang was measured between the resected lateral part of the posterior femur and its corresponding component size, and the two designs were compared in three zones (proximal, central, and distal). Results In the simulated femoral component, the asymmetric design had a significantly lower component overhang than the symmetric design in the proximal zone of the lateral posterior condyle (0.2±1.9 mm vs. 3.5±1.6 mm, p<0.01). In the proximal zone, significant overhang (>3 mm) was observed in 30 knees (60.0%) with the symmetric design, but only three knees (6.0%) had asymmetric designs (p<0.01). Conclusions The posterolateral overhang of the lateral posterior condyle occurs when a symmetrical prosthesis is used. The use of an asymmetric implant with a small, rounded proximal portion of the lateral posterior condyle improves this overhang and is expected to decrease problems such as impingement of the popliteus tendon and improve patient satisfaction.

Optimal Intermittent Administration Interval of Abaloparatide for Bone Morphogenetic Protein-Induced Bone Formation in a Rat Spinal Fusion Model.

Both bone morphogenetic protein 2 (BMP-2) and abaloparatide are used to promote bone formation. However, there is no consensus about their optimal administration. We investigated the optimal administration theory for the pairing of BMP-2 and abaloparatide in a rat spinal fusion model. Group I was only implanted in carriers and saline. Carriers with 3 µg of recombinant human BMP-2 (rhBMP-2) were implanted in other groups. Abaloparatide injections were administered three times a week for group III (for a total amount of 120 µg/kg in a week) and six times a week for group IV (for a total amount of 120 µg/kg in a week) after surgery. They were euthanized 8 weeks after the surgery, and we explanted their spines at that time. We assessed them using manual palpation tests, radiography, high-resolution micro-computed tomography (micro-CT), and histological analysis. We also analyzed serum bone metabolism markers. The fusion rate in Groups III and IV was higher than in Group I, referring to the manual palpation tests. Groups III and IV recorded greater radiographic scores than those in Groups I and II, too. Micro-CT analysis showed that Tbs. Sp in Groups III and IV was significantly lower than in Group I. Tb. N in Group IV was significantly higher than in Group I. Serum marker analysis showed that bone formation markers were higher in Groups III and IV than in Group I. On the other hand, bone resorption markers were lower in Group IV than in Group I. A histological analysis showed enhanced trabecular bone osteogenesis in Group IV. Frequent administration of abaloparatide may be suitable for the thickening of trabecular bone structure and the enhancement of osteogenesis in a rat spinal fusion model using BMP-2 in insufficient doses.

Influence of etching mode on bonding performance of self-adhesive flowable resin composites to bovine teeth.

This study aimed to evaluate the bonding performance of self-adhesive flowable resin composites (SARs) to bovine teeth. Three SARs, one experimental, and two commercially available products, were used. The study parameters were shear bond strength (SBS), microleakage, and scanning electron microscopy (SEM) evaluation of bonding interfaces. The SBS of the materials was 14.1-15.1 MPa to enamel, 22.2-23.2 MPa to etched enamel, and 7.4-10.7 MPa to dentin. Specimens with pre-etching showed lower microleakage scores than those without pre-etching. SEM images of the interfaces of the materials showed excellent adaptation regardless of the substrate or etching mode. The study results indicate that enamel pre-etching can improve the bonding performance of SARs.

Scanning electron microscopy observation of dentin bond interfaces in different types of resin luting cements.

This study aimed to observe and compare the resin luting cement (RLC)/dentin interfaces of different types of RLC systems with scanning electron microscopy (SEM). This study evaluated six self-adhesive resin luting cement systems (SARLCs), four systems combining a SARLC with a tooth primer (SARLCPs), and six conventional resin luting cement systems (CVRLCs). Cured resin composite rods were bonded to bovine dentin using RLCs in different etching modes. The morphological features at the interfaces were observed using SEM. Although all RLCs in etch-&-rinse (ER) mode showed a clear hybrid layer, most SARLCs had a thinner and more porous hybrid layer than the SARLCPs and CVRLCs. All SARLCPs with primer and CVRLCs showed a thin high-density layer below the primer layer in both etching modes. CVRLCs and SARLCPs with primer treatment systems may be more versatile and reliable when compared to simplified RLC systems.

Influence of different curing modes on the bonding effectiveness of self-adhesive resin luting cements in combination with universal adhesives.

OBJECTIVES: This study aimed to investigate the immediate dentin bond performance and bond durability of self-adhesive resin luting cements (RLCs) in combination with universal adhesives in different curing modes. METHODS: Two self-adhesive RLCs were used with universal adhesives as primers. They were also used alone as self-adhesive RLCs. Two multiple-step RLC systems were used as comparison materials. To measure the shear bond strength (SBS) in different curing modes, 12 specimens were prepared for each group. Stainless-steel rods were bonded to bovine dentin, and the bonded specimens were assigned to the baseline group (stored for 24 h) and artificially aged group (thermal cycling [TC], 10,000 cycles). After each storage period, the SBS of the bonded specimens was measured. The Knoop hardness number (KHN) of the cured RLCs was measured with or without primer application in different curing modes at 24 h and after 10,000 TC. The representative RLC/dentin interfaces were observed using scanning electron microscopy (SEM). RESULTS: Dentin SBS was significantly influenced by the RLC system but not by the curing mode. Self-adhesive RLCs alone showed significantly lower SBS values than self-adhesive RLCs with primer regardless of the curing mode or storage period. The storage period, curing mode, and RLC system significantly influenced the KHN. SIGNIFICANCE: The use of universal adhesives as a primer may help enhance the immediate dentin bond performance and bond durability of self-adhesive RLCs.

Early Versus Delayed Surgery for Elderly Traumatic Cervical Spinal Injury: A Nationwide Multicenter Study in Japan.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: The effectiveness of early surgery for cervical spinal injury (CSI) has been demonstrated. However, whether early surgery improves outcomes in the elderly remains unclear. This study investigated whether early surgery for CSI in elderly affects complication rates and neurological outcomes. METHODS: This retrospective multicenter study included 462 patients. We included patients with traumatic acute cervical spinal cord injury aged ≥65 years who were treated surgically, whereas patients with American Spinal Injury Association (ASIA) Impairment Scale E, those with unknown operative procedures, and those waiting for surgery for >1 month were excluded. The minimum follow-up period was 6 months. Sixty-five patients (early group, 14.1%) underwent surgical treatment within 24 hours, whereas the remaining 397 patients (85.9%) underwent surgery on a standby basis (delayed group). The propensity score-matched cohorts of 63 cases were compared. RESULTS: Patients in the early group were significantly younger, had significantly more subaxial dislocations (and fractures), tetraplegia, significantly lower ASIA motor scores, and ambulatory abilities 6 months after injury. However, no significant differences in the rate of complications, ambulatory abilities, or ASIA Impairment Scale scores 6 months after injury were observed between the matched cohorts. At 6 months after injury, 61% of the patients in the early group (25% unsupported and 36% supported) and 53% of the patients in the delayed group (34% unsupported and 19% supported) were ambulatory. CONCLUSIONS: Early surgery is possible for CSI in elderly patients as the matched cohort reveals no significant difference in complication rates and neurological or ambulatory recovery between the early and delayed surgery groups.

Performance Evaluation of the Commonly-Used Portable Cholesterol Sensors for Telehealth Services in the Unreached Communities.

Portable medical sensors play an important role in healthcare services, especially in rural communities. Many telehealth systems use these devices for providing patients' vital information from a distance to remote doctors. Erroneous data will not only mislead the remote doctor for correct diagnosis but it will cause health threats to these unreached community people. Therefore, it is very important to identify good sensors with an acceptable level of accuracy but within the affordable price of the available sensors in the market. This study aims to identify quality portable cholesterol sensors with high accuracy with the reference of the Japanese clinical pathology laboratory as a gold standard. We have considered cholesterol sensors that measure total cholesterol for this study that are commonly used in the developing countries of Asia. We found that out of four, three of them were very much erroneous and cannot be recommended even for primary healthcare.

Treatment of saliva contamination of resin core foundation before adhesive luting.

This study aimed to evaluate the influence of surface pretreatment on the shear bond strength of resin luting cement to saliva-contaminated resin core foundation. The surface free energy (γS) of the adherent surfaces was examined. The two-way analysis of variance revealed that the surface pretreatment and storage conditions had a significant effect on the strength of the bond to resin core foundation. The γS values of the saliva-contaminated group were significantly lower than those of the other groups, and they tended to improve after surface pretreatment. The tendency of improvement in γS values differed depending on the type of pretreatment agents. Surface treatment with solutions containing functional monomers is effective in removing saliva contaminants from the resin core foundation surfaces and in creating an effective bonding surface for the resin luting cement.

Effectiveness of gelatin matrix with human thrombin for reducing blood loss in palliative decompressive surgery with posterior spinal fusion for metastatic spinal tumors.

BACKGROUND: This study aimed to investigate the effect of gelatin matrix with human thrombin (GMHT) on blood loss and survival time in patients with metastatic spinal tumors treated with palliative decompression surgery with posterior spinal fusion. METHODS: We retrospectively reviewed 67 consecutive patients with metastatic spinal tumors who underwent palliative decompression surgery with posterior spinal fusion. We compared patients in whom GMHT was not used during surgery with those in whom GMHT was used. The following baseline characteristics were evaluated: age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, Karnofsky Performance Status score, Charlson comorbidities index score, the percentage of patients who received perioperative chemotherapy, main tumor level, Frankel category, revised Tokuhashi score, spinal instability neoplastic score (SINS), number of fusion segments, operation time, intraoperative blood loss, drainage blood loss, red blood cell transfusion, hemoglobin level, total protein (TP), albumin values, total blood loss (TBL), hidden blood loss, postoperative bed rest and postoperative survival time. Perioperative complications were assessed. RESULTS: Age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, CCI score, main level of tumors, SINS score, preoperative Tokuhashi score and number of fusion segments did not differ significantly between the two groups. Operation time, intraoperative blood loss, postoperative drainage blood loss, and TBL were significantly decreased in the group with GMHT than in the group without GMHT. The total number of perioperative complications was significantly lesser in the group with GMHT than in the group without GMHT. The median postoperative survival time was significantly longer in the GMHT group than in the group without GMHT. CONCLUSION: GMHT should be considered a valid option for the treatment of patients with metastatic spinal tumors with a short life expectancy.

A nationwide multicenter study of the cost effectiveness of five leading drugs for pharmacological management of cervicobrachial symptoms.

BACKGROUND: Cervicobrachial pain frequently affects the quality of life (QOL) of the general public and has a significant economic impact on the health care systems of various countries. There are a number of treatment options for this disease, including widely-used drug therapy, but the effectiveness of each option is indeterminate, and there have been no published cost-effectiveness analysis studies so far. This prospective observational study aimed to examine the cost-effectiveness of drug treatment for cervicobrachial symptoms. METHODS: A 6-month medication regimen for each of five frequently-prescribed drugs for cervicobrachial symptoms was administered to 322 patients at 24 centers in Japan. Outcome measures, including of the EuroQol Group 5D, Short Form-8, and Visual Analog Scale (VAS), were investigated at baseline and every month thereafter. Incremental cost-effectiveness ratios (ICERs) of the drug cost to quality-adjusted life years (QALYs) were calculated. A stratified analysis of patient characteristics was also performed to identify baseline factors potentially affecting cost-effectiveness. RESULTS: The ICER of entire drug treatment for cervicobrachial symptoms was 7,491,640 yen. Compared with the reference willingness-to-pay, the ICER was assumed to not be cost-effective. A certain number of QALYs were gained during the first 3 months after the treatment intervention, but almost no QALYs were gained during the following 3 months. Stratified analysis showed that cost-effectiveness was extremely low for patients with high baseline VAS and high QOL. CONCLUSIONS: The available medications for cervicobrachial symptoms did not have excellent cost-effectiveness. Although a certain number of QALYs were gained during the first 3 months after medication, no QALYs were gained in the latter half of the study period, suggesting that it is not advisable to continue the medication needlessly. LEVEL OF EVIDENCE: II, prospective cohort study.

Small Molecules Temporarily Induce Neuronal Features in Adult Canine Dermal Fibroblasts.

Several methods have been developed to generate neurons from other cell types for performing regeneration therapy and in vitro studies of central nerve disease. Small molecules (SMs) can efficiently induce neuronal features in human and rodent fibroblasts without transgenes. Although canines have been used as a spontaneous disease model of human central nerve, efficient neuronal reprogramming method of canine cells have not been well established. We aimed to induce neuronal features in adult canine dermal fibroblasts (ACDFs) by SMs and assess the permanency of these changes. ACDFs treated with eight SMs developed a round-shaped cell body with branching processes and expressed neuronal proteins, including ßIII-tubulin, microtubule-associated protein 2 (MAP2), and neurofilament-medium. Transcriptome profiling revealed the upregulation of neuron-related genes, such as SNAP25 and GRIA4, and downregulation of fibroblast-related genes, such as COL12A1 and CCN5. Calcium fluorescent imaging demonstrated an increase in intracellular Ca2+ concentration upon stimulation with glutamate and KCl. Although neuronal features were induced similarly in basement membrane extract droplet culture, they diminished after culturing without SMs or in vivo transplantation into an injured spinal cord. In conclusion, SMs temporarily induce neuronal features in ACDFs. However, the analysis of bottlenecks in the neuronal induction is crucial for optimizing the process.

Dome impaction classification in acetabular fractures: Identifying atypical dome impactions with absence of the gull sign: A retrospective descriptive study.

We aimed to describe variations of dome impaction fractures and their characteristics using a new classification system, to explore the relationship between dome impaction and the gull sign. The present study was a retrospective descriptive study. All 104 cases of acetabular fracture that were treated in our institution from 2013 to 2022 were enrolled. Of these, 22 had dome impaction fractures. The primary outcome variable was to describe the variations and characteristics of dome impaction fractures. They were classified into 3 major subgroups based on reconstructed axial, coronal, and sagittal computed tomography findings: anteromedial, superomedial (SM), and posteromedial. The secondary outcome variable was to explore the relationship between dome impaction on computed tomography findings and the gull sign on plain radiographs. There were 4 cases of anteromedial (18.2%), 13 of SM (59.1%), and 5 of posteromedial (22.7%). There were 15 cases (68.2%) with the gull sign and 7 cases (31.8%) without the gull sign on plain radiographs. Twelve of fifteen cases (80.0%) with the gull sign had dome impaction fractures of the SM type. We found a variety of patterns of dome impaction fracture. Surgeons should be aware of atypical dome impactions not showing the gull sign.

Efficacy of gelatin-thrombin matrix sealants for blood loss in single-level transforaminal lumbar interbody fusion.

Although gelatin-thrombin matrix sealants have been used successfully in other surgery types, their effect on reducing blood loss during single-level transforaminal lumbar interbody fusion is unclear. We thus examined the efficacy of gelatin-thrombin matrix sealants for reducing blood loss during such surgery. We analyzed 102 patients who underwent single-level transforaminal lumbar interbody fusion for lumbar degenerative disease. We compared body mass index, surgical time, intraoperative blood loss, postoperative blood loss, true total blood loss, hidden blood loss, the proportion of blood transfusion, blood pressure pre- and post-surgery (systolic and diastolic), and pre-and post-surgery laboratory data (hemoglobin, hematocrit, platelets, prothrombin time, activated partial thromboplastin time, and D-dimer) between patients in whom gelatin-thrombin matrix sealants were (GTMS group) or were not (control group) used during surgery. One-week postoperative epidural hematoma size was measured using magnetic resonance imaging. The GTMS and control groups included 54 (24 males and 30 females) and 48 patients (19 males and 29 females). Intraoperative, true total, and hidden blood loss; epidural hematoma size; and hospitalization duration were significantly lower in the GTMS than in the control group. Intraoperative blood loss correlated with surgical time (R = 0.523, P = .001), body mass index (R = 0.221, P = .036), and the amount of gelatin-thrombin matrix sealant used (r = -0.313, P = .002). In multivariate linear regression analysis using intraoperative blood loss as the dependent variable, surgical time (standardization coefficient 0.516, P = .001) and amount of gelatin-thrombin matrix sealant used (standardization coefficient -0.220, P = .032) were independently related factors. In our study, the GTMS group had significantly less intraoperative true total and hidden blood loss than did the control group. Thus, use of gelatin-thrombin matrix sealants reduce perioperative blood loss in transforaminal lumbar interbody fusion.

Influence of surface roughness of universal shade resin composites on color adjustment potential.

This study aimed to determine the influence of surface roughness of the color adjustment potential restoration of universal resin composites. A structural colored resin composite (Omnichroma, OC) and a pigment-employed universal shade resin composite (Beautifil Unishade, BU) were used. Each resin composite was placed in a cavity to determine its ability to match the color of artificial teeth. The surface of the resin composites was polished with #800- or #2000-grit SiC paper before performing color measurements. One-way analysis of variance and Tukey post hoc tests were performed (α=0.05). The color difference (ΔE*ab) ranged from 2.5-3.9 for OC and 1.8-8.7 for BU. OC has a more stable color adjustment than BU. The color adjustment potential of universal resin composites was affected by the surface roughness of the restorations.

Worsening ambulation in elderly patients with cervical odontoid fractures: A nationwide multicenter study in Japan.

BACKGROUND: Despite the increasing prevalence of cervical odontoid fractures in older adults, the treatment strategy is controversial. The objectives of the current study are to investigate the prognosis and complications of cervical odontoid fractures in elderly patients and to identify factors associated with worsening of ambulation after 6 months. METHODS: This multicenter, retrospective study included 167 patients aged 65 years or older with odontoid fractures. Patient demographic and treatment data were investigated and compared according to the treatment strategy. To determine associations with worsening ambulation after 6 months, we focused on the treatment strategies (nonsurgical treatment [collar immobilization or halo vest], conversion to surgery, or initial surgery) and patients' background. RESULTS: Patients who received nonsurgical treatment were significantly older, and patients who underwent surgery had more Anderson-D'Alonzo type 2 fractures. Of the patients initially treated nonsurgically, 26% later underwent surgery. Numbers of complications, including death, and degrees of ambulation after 6 months did not differ significantly among treatment strategies. Patients who had worsened ambulation after 6 months were significantly more likely to be older than 80 years, to have needed assistance with walking before injury, and to have cerebrovascular disease. Multivariable analysis showed that a score of ≥2 on the 5-item modified frailty index (mFI-5) was significantly associated with worsening ambulation. CONCLUSIONS: Preinjury mFI-5 scores of ≥2 were significantly associated with worsening ambulation 6 months after treatment of cervical odontoid fractures in older adults.

Analysis of accuracy of pedicle screw placement in dysplastic pedicles in adolescent idiopathic scoliosis using the pedicle expansion technique with CT-based navigation.

BACKGROUND: This study aimed to study the accuracy of pedicle screw (PS) insertion into dysplastic pedicles in adolescent idiopathic scoliosis (AIS) comparing cannulated screw using the pedicle expansion technique (PET) versus conventional technique. METHODS: Forty-two AIS patients with 766 PSs were evaluated. In total, 236 screws were inserted into dysplastic pedicles: 138 and 98 screws were inserted using the PET (PET group) and standard technique (conventional group), respectively. Both methods used CT-based navigation to determine the insertion point. In the PET, a rigid ball tip feeler was tapped with a mallet to create an insertion route, a guide wire was passed through the tap, the pedicle was enlarged, and then a cannulated PS with a diameter of 4.35 mm was inserted. Postoperative CT was used to compare the accuracy of PS insertion. RESULTS: In total, 23/236 (9.7%) perforations occurred. Regarding overall perforation, there were six (4.3%) and 17 (17.3%) cases in the PET and conventional group, respectively (P = 0.008). In terms of medial perforation, the PET group (n = 2, 1.4%) was significantly better than the conventional group (n = 7, 7.1%) (P = 0.021). In terms of lateral perforation, the PET group (n = 4, 2.9%) was significantly better than conventional group (n = 10, 10.2%) (P = 0.030). Only grade 1 perforation had occurred in the PET group, whereas grades 2 and 3 perforation occurred in the conventional group. CONCLUSION: Use of the PET with CT-based navigation significantly increased the accuracy and safety of PS insertion in dysplastic pedicles in AIS.

Whitening efficacy and tooth sensitivity in a combined in-office and at-home whitening protocol: A randomized controlled clinical trial.

OBJECTIVE: This controlled randomized clinical trial determined the whitening efficacy and the intensity and absolute risk of tooth sensitivity in dual whitening when prefilled at-home whitening trays were used between in-office whitening intervals. MATERIALS AND METHODS: An in-office whitening agent containing 35% hydrogen peroxide was used. A prefilled tray with a whitening agent containing 6% hydrogen peroxide was used for at-home whitening. Sixty-six subjects were randomly assigned to three groups. Group I: at-home whitening was performed 10 times between the in-office whitening treatments. Group II: at-home whitening was performed five times between the in-office whitening treatments. Group III: only in-office whitening was performed. The tooth color changes were evaluated using a spectrophotometer. A visual analog scale was used to express the pain intensity. RESULTS: All the groups showed increased ΔE*ab, ΔE00 , and ΔWID with increased whitening sessions. Group I at the 3rd whitening session showed significantly higher ΔE*ab, ΔE00 , and ΔWID than group III. Tooth sensitivity showed higher values up to 24 h after whitening. CONCLUSIONS: Although dual whitening with the prefilled tray and in-office whitening had higher whitening ability than in-office whitening alone, the intensity and absolute risk of tooth sensitivity was similar. CLINICAL RELEVANCE: The dual whitening might produce faster and stronger whitening effects than in-office whitening alone.

Intractable arteriovenous access-related pain relieved after a single, pain-free hemodialysis session under selective block of the sensory nerves in the upper limb: A psychosocial factorial case.

Intractable arteriovenous access (AVA)-related pain can not only lead to abandonment of a well-functioning AVA, but can also cause hemodialysis (HD) patients to be unwilling to accept, interrupt, or withdraw from HD. Such pain primarily derives from nociceptive and neuropathic factors caused by mechanical stimulation of needle cannulation; however, this might be related to psychosocial factors making it difficult for patients to accept their dependency on HD. Furthermore, the pain can be complicated by the interaction of biological and psychosocial factors, which hampers appropriate pain management and treatment. However, there have been few investigations pertaining to this matter. Herein, we describe the case of an HD patient who experienced chronic refractory AVA-related pain during a 32-month period of HD sessions, which occasionally caused treatment interruption. After clinical inquiry, physical evaluation, and ultrasonographic assessment of the blood circulation and cutaneous nerves in the ipsilateral upper limb to the radiocephalic arteriovenous fistula in the anatomical snuffbox, we diagnosed the patient with primarily psychosocially driven pain in consultation with an experienced pain clinician. A single, pain-free HD session under ultrasound-guided sensory nerve blocks in the upper limb markedly relieved her pain, followed by HD sessions with subtle but acceptable pain. This report provides insights into the mechanism underlying the vicious cycle of AVA-related pain, including the psychosocial aspects that might trigger such pain, as well as into the importance of treating such pain to improve the patient's quality of life, and underscores the need for cooperation of experts engaged in HD and pain management.

Anesthetic effect of ultrasound-guided block of the musculocutaneous nerve during endovascular treatment of dysfunctional radiocephalic arteriovenous fistulas.

BACKGROUND: Delivering requisite and minimal anesthesia for endovascular treatment (EVT) of dysfunctional arteriovenous fistulas (AVFs) under the target nerve block can achieve reasonable analgesia. We evaluated the anesthetic efficacy of ultrasound (US)-guided selective block of the musculocutaneous nerve (MCN) during the EVT of runoff venous strictures in the forearm through the radiocephalic (RC)-AVF at the wrist or the anatomical snuff box and analyzed the factors inhibiting the analgesia achieved under the MCN block. METHODS: We enrolled 30 adult patients undergoing hemodialysis who had received 78 EVT sessions in an outpatient clinic mainly for long and/or multiple outflow-venous strictures in the forearm under US-guided blocks of the MCN, which provides sensory innervation to the anterolateral forearm where the cephalic vein courses. We assessed patients' pain during balloon dilations using the Wong-Baker FACES® Pain Rating Scale (WBFRS) and evaluated the factors increasing the pain (WBFRS score ⩾4), including patient characteristics, dilated strictures, additional nerve blocks, and types of balloon catheters. RESULTS: In 25 EVT sessions (32.1%) out of 78 sessions, patients complained of stronger pain (WBFRS score ⩾4), while in the other 53 sessions (67.9%), presented with no pain and slight pain (WBFRS score = 0 or 2). Univariate analysis clarified that dilation of the AVF anastomosis, presence of dilated stenosis >4 cm, and a single block of the MCN or its sensory terminal significantly triggered more pain (p < 0.05). Consequently, multivariate analysis of all the factors with p < 0.1 in the univariate analysis, including multiple dilated stenosis sites, demonstrated that dilation of the AVF anastomosis significantly caused severe pain despite the anesthesia of the MCN block (p < 0.05). CONCLUSION: US-guided selective block of the MCN could be a leading anesthetic option for EVT for multiple long stenoses of the cephalic vein draining through the RC-AVF in the wrist or anatomical snuff box.

Transposition of the superficial femoral artery combined with ultrasound-guided returning-venous cannulation as a last resort for vascular access in a multi-complicated hemodialysis patient.

A superficialized artery as a blood-drawing route could be an option for vascular access (VA) in hemodialysis patients with cardiac failure, vessel damage, steal syndrome, and venous hypertension, and it could be a secondary VA option in those with repetitive vascular access troubles, routinely requiring a blood-returning venous route. The brachial artery is preferably used for superficialization due to the benefit of its appropriate diameter for cannulation, procedural ease of surgery under local anesthesia, and usable subcutaneous vein for blood-returning route in the upper limb. The superficial femoral artery (SFA) has also been reported as a candidate for arterial transposition; however, its subcutaneous transposition could have difficulties in requiring general anesthesia and securing blood-inflow-venous routes. We experienced a multi-complicated hemodialysis patient who had intractable tunneled-cuffed catheter-related bacteremia and right atrial thrombosis, low cardiac function with bilateral proximal bifurcation of the brachial artery at the axilla, and damaged cutaneous veins in the upper limb. Herein, we report a case of successful superficialization of the SFA under ultrasound-guided regional anesthesia combined with local anesthesia and intravenous sedation, which could be feasible as a blood-drawing route with ultrasound-guided ipsilateral greater saphenous vein cannulation during chronic hemodialysis. Assisted by ultrasound-guided venous cannulation in the ipsilateral lower limb, cutaneous repositioning of the SFA could be a viable and acceptable option for VA in hemodialysis patients with a multitude of complications, wherein the possibilities of VAs of arteriovenous access, arterial superficialization using vessels in the upper extremity, or artificial devices should be eliminated.