Nagoya Journal of Medical Science最新文献

The segmental innervation patterns of lower extremity muscles remain poorly defined, despite their critical importance in both clinical diagnosis and surgical planning for lumbar spinal conditions. Variability in these patterns, particularly under chronic nerve root compression, complicates the development of accurate diagnostic and therapeutic strategies. This study aimed to elucidate the segmental innervation patterns of lower extremity muscles through intraoperative nerve root stimulation during lumbar spinal surgery combined with motor evoked potential (MEP) during lumbar spinal surgery. A total of 30 patients diagnosed with unilateral nerve root impairment due to degenerative lumbar canal stenosis were enrolled in this study. All patients provided informed consent, demonstrated lower extremity muscle strength graded 4 or higher on the manual muscle test, and were scheduled for surgeries that enabled direct visualization of bilateral nerve roots. During the surgical procedures, 128 lumbosacral nerve roots (L2-S1) were stimulated using a monopolar stimulator, and MEPs were recorded from key lower extremity muscles, including the vastus lateralis, tibialis anterior, and medial gastrocnemius. The vastus lateralis muscle was consistently innervated by the L2 root in 100% of cases, confirming a stable and reproducible pattern. In contrast, stimulation of the L5 root revealed notable anomalies in 8% of cases, where compensatory mechanisms or anatomical anomalies appeared to alter the expected innervation patterns. Furthermore, differences in muscle innervation between the left and right sides were observed in 39% of tested nerve roots, with variability being particularly pronounced in lower lumbar levels, such as L4, L5, and S1.

Sarcopenia, a condition characterized by the loss of muscle mass and function, poses a major health challenge among older adults. Identifying nutritional factors and dietary patterns associated with sarcopenia is critical for developing targeted interventions. This study analyzed data from 584 community-dwelling older adults (245 male, 339 female) enrolled in the Yakumo Study to investigate the relationship between dietary factors and sarcopenia. Nutritional intake was assessed using a validated Food Frequency Questionnaire (FFQ), while dietary diversity was evaluated using dietary variety score (DVS). Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia (AWGS) criteria, based on skeletal muscle mass, hand grip strength, and walking speed. The prevalence of sarcopenia in the study population was 7.4%. Nutritional intake of individual nutrients, such as protein and vitamin D, did not significantly differ between sarcopenic and non-sarcopenic participants. However, the intake rates for total calories, dietary fiber, vitamin B1, vitamin B2, and vitamin C were significantly higher in the sarcopenia group. No significant differences were found in DVS, and no correlations were found between DVS scores and skeletal muscle mass index, grip strength, or walking speed. These results may indicate that factors beyond nutrient intake-such as nutrient absorption, utilization, and metabolic efficiency-play a pivotal role in sarcopenia development.

Calcium chloride (CaCl₂)-containing carbon dioxide (CO₂) absorbers are characterized by their ability to produce almost no pentafluoroisopropenyl fluoromethyl ether (Compound A), a potentially nephrotoxic byproduct of sevoflurane, in vitro. However, the precise role of CaCl₂ in this process remains unclear. We aimed to clarify the role of CaCl₂ in vitro and determine whether CaCl₂-containing CO₂ absorbents produce Compound A during prolonged surgery under low- and minimal-flow sevoflurane anesthesia using Japanese brand Yabashi Lime-f (YL-f). In vitro, a reaction between 1 L of sevoflurane gas (8%) with 5% CO₂ and an absorbent specimen (20 g) with or without water was performed in an artificial closed-circuit system for 15 or 60 min at 45 °C. In vivo, patients scheduled for colorectal resection received 2.0 vol% sevoflurane at fresh gas flows of 2.0, 1.0, or 0.5 L/min (N = 6) with YL-f. Gas samples from the anesthetic circuit were collected 6 h after induction and at the conclusion of surgeries lasting over 7 h. Compound A concentrations were measured using gas chromatography-flame ionization detection. Compound A production was observed in CaCl₂-free absorbents but not in those containing CaCl₂ in vitro. During 60-min reactions, CaCl₂-free YL-f derivatives produced a median 3.5 ppm of Compound A, with higher concentrations (7.1 ppm) observed upon the addition of 3 mL of water. YL-f did not produce Compound A, regardless of the presence of water. Compound A was not detected in in vivo samples. In conclusion, CaCl₂ suppresses Compound A production from sevoflurane, likely by trapping water within the anesthetic circuit.

Cerebrospinal fluid (CSF) leakage is a common and serious complication of spinal surgery, particularly after intradural tumor resection. CSF leakage can lead to debilitating headaches, neurological deficits, and other symptoms, with an incidence rate of 0.3%-16%. This study aimed to investigate the incidence, risk factors, and outcomes of CSF-related complications in patients who underwent spinal intradural tumor surgery. This was a retrospective cohort study including 102 patients who underwent resection of intradural tumors, including ependymomas, astrocytomas, and meningiomas. Data were collected, including patient demographics, surgical details, and postoperative outcomes. The extent of CSF accumulation was evaluated using magnetic resonance imaging (MRI) findings. Statistical analyses were performed to identify risk factors for symptomatic CSF leakage. Postoperative CSF accumulation was observed in 94.1% of patients. Among them, 28.1% experienced symptomatic complications, such as severe headache (20.8%), unexplained fever (6.3%), and CSF leakage (3.1%). Patients with larger CSF accumulation, particularly subcutaneous accumulation, had a significantly higher incidence of symptomatic complications, with the highest rate observed in subfascial accumulation cases (P = 0.0002). Symptomatic patients did not show significant differences in age, sex, surgical level, drainage duration, or blood loss compared to asymptomatic patients. Additionally, the use of artificial dura mater did not significantly affect symptomatic outcomes. Predicting the occurrence of symptoms based on preoperative and surgical factors remains challenging. However, patients with subfascial CSF accumulation were more likely to develop symptoms, highlighting the necessity of confirming CSF accumulation using MRI for appropriate postoperative management.

The adoption of lumbar fusion techniques, particularly lateral lumbar interbody fusion (LLIF), has significantly evolved the management of degenerative lumbar spinal conditions. LLIF, introduced as a minimally invasive surgical procedure, offers the advantage of indirect neural decompression and robust bone fusion using large interbody cages, reducing complications such as cage subsidence and nerve injuries. Systematic reviews have indicated that LLIF was effective for foraminal decompression, although evidence regarding its effectiveness for spinal canal and lateral recess decompression remains limited. Comparisons between indirect decompression techniques like LLIF and direct methods (posterior lumbar interbody fusion and transforaminal lumbar interbody fusion) have revealed that while indirect approaches generally promoted lower surgical times and blood loss, outcomes related to pain, disability, and complications were comparable. Indirect decompression with LLIF should be approached cautiously or avoided in patients with severe stenosis or preoperative neurological impairments due to the increased risk for postoperative complications. Furthermore, meticulous surgical planning and advanced imaging techniques are essential for mitigating risks such as vascular, bowel, and ureteral injuries. Continued advancements in surgical instrumentation and navigation technologies are expected to further refine the utility of LLIF in treating complex spinal pathologies, offering a promising minimally invasive option for achieving effective spinal stabilization and decompression.

Pemetrexed, a structural antifolate agent that is eliminated via renal excretion, is commonly used to treat non-squamous non-small-cell lung cancer (NS-NSCLC). Although poor renal function is associated with a high incidence of toxicities, the association of high renal function with chemotherapy efficacy and toxicity remains unknown. We aimed to investigate the effect of renal function on the efficacy and toxicity of carboplatin-pemetrexed chemotherapy in patients with NS-NSCLC. We performed a post-hoc analysis of a prospective observational study of carboplatin-pemetrexed treatment in NS-NSCLC patients. Baseline renal function was calculated using the Japanese estimated glomerular filtration rate (eGFR) formula, and the patients were then divided into two groups based on the eGFR: high-eGFR (eGFR ≥ 80 mL/min/1.73 m², N = 162) and low-eGFR (eGFR < 80 mL/min/1.73 m², N = 176) groups. Although the response rates in the high- and low-eGFR groups were similar (22.2% vs 23.9%, P = 0.7205), the disease control rate was significantly lower in the high-eGFR group than in the low-eGFR group (75.9% vs 84.7%, P = 0.043). Progression-free survival (PFS) and overall survival (OS) in the high-eGFR group were significantly shorter than those in the low-eGFR group (adjusted hazard ratio for PFS and OS, 1.32 [95% CI, 1.04-1.69; P = 0.0245] and 1.49 [95% CI, 1.15-1.93, P = 0.0023], respectively). The incidence of hematological and non-hematological toxicities was lower in the high-eGFR group. In conclusion, a high-eGFR is associated with poor efficacy and mild toxicity of carboplatin-pemetrexed in patients with NSCLC.

While preoperative antibiotic therapy is generally recommended in non-emergency surgery cases of infective endocarditis, delaying surgery may lead to a deterioration in patient condition. This study examined deterioration of condition during preoperative antibiotic therapy and associated clinical characteristics to clarify the optimal timing for non-emergent infective endocarditis surgery. We retrospectively analyzed 65 patients (mean age 57.1 ± 16.9 years) with active left-sided infective endocarditis (57 with native valves, 8 with prosthetic valves) initially considered suitable for combined antibiotic therapy and non-emergent surgical treatment. Causative organisms were Streptococcus spp. (n=31), Staphylococcus spp. (n=15, including 5 resistant strains), and Gram-negative bacteria (n=4). Twelve patients (18%) required unexpected urgent operations shortly after starting antibiotics (median 5.5 days, interquartile range 3-8 days). Another 12 patients (18%) experienced deterioration of condition 20-30 days after starting antibiotics, including worsening heart failure (n=5), new embolic events (n=3), new perivalvular extension of infection (n=3), and worsening infection parameters (n=1). A leukocyte count >7900/μL one week after starting antibiotics predicted late deterioration (sensitivity 91%, specificity 76%, area under the receiver operating characteristic curve 0.866). Among patients with active infective endocarditis who initially received maximal antibiotic therapy and were considered for non-emergent surgery, 18% required urgent operation and another 18% experienced late deterioration. A high leukocyte count despite one week of antibiotic therapy was associated with late deterioration. For these patients, earlier surgical intervention might be beneficial to avoid a deterioration in conditions.

Bone regeneration is a highly demanded but challenging clinical endeavor in orthopedic surgery, necessitating the development of alternative bone grafting materials. This study aimed to evaluate the bone regenerative potential of self-assembling peptide hydrogel (0.8%), bone morphogenetic protein-2 (50 ng/μL), hydroxyapatite, and β-tricalcium phosphate, both individually and in combination with bone chips, in a rat femoral defect model. Ten-week-old female Wistar rats underwent surgical implantation of a polyetheretherketone cage into a 5-mm bony defect within the left femoral mid-shaft, maintained by an external fixator. Polyetheretherketone cages were filled with bone substitute materials alone in the first experiment and with bone substitute materials combined with bone chips in the second experiment. Radiographic and histological analyses were conducted following sacrifice at 56 weeks. While self-assembling peptide hydrogel alone exhibited moderate bone formation, with a bone-volume-to-total-volume ratio of 0.34 ± 0.09, this value was not significantly higher than that of the control group with an empty polyetheretherketone cage. Conversely, the combination of bone morphogenetic protein-2 with bone chips produced the highest level of bone regeneration, with a bone-volume-to-total-volume ratio of 0.78 ± 0.05, significantly surpassing bone chips alone (p < 0.01) and self-assembling peptide hydrogel with bone chips (p < 0.05). These findings suggest that while self-assembling peptide hydrogel holds potential as a scaffold material, particularly in minimally invasive applications, its efficacy in promoting robust bone regeneration may benefit from the inclusion of osteoinductive factors, such as bone morphogenetic protein-2.

We report the case of an 80-year-old woman with a medial thigh nodule who was diagnosed with primary cutaneous diffuse large B-cell lymphoma, leg type. Further examination identified it as double-expressor lymphoma with elevated expression of both MYC and BCL2. This elevated expression has been linked to MYC translocation and is likely associated with trisomy 18. Our findings suggest that trisomy 18 plays a significant role in the development of double-expressor lymphoma. While cases of double-expressor lymphoma caused by extra copies of BCL2 have been reported, we could not find any case of double-expressor lymphoma caused by trisomy 18. Therefore, this is an unique case of double-expressor lymphoma linked to MYC rearrangement and trisomy 18. Double-expressor lymphoma typically has a poor prognosis and is often resistant to standard treatments. The current findings may help refine diagnostic strategies for this condition.

Shear wave elastography provides quantitative data on tissue stiffness, but was not available for endoscopic ultrasound until recently. The present study investigated the utility of a newly developed endoscopic ultrasound-guided shear wave measurement for diagnosing upper gastrointestinal subepithelial lesions. Shear wave velocity (Vs) was measured as an indicator of tissue stiffness, and the total amount of effective shear waves (VsN) was used as a reliability index for Vs values obtained by endoscopic ultrasound-guided shear wave measurements. Among the Vs values obtained, the five with the highest VsN were selected, and their median was defined as the median Vs (Vs-med). The median VsN of the five Vs values was defined as the median VsN (VsN-med). Endoscopic ultrasound-guided shear wave measurements were performed on 23 patients, with no complications occurring in any procedure. Histopathological diagnoses included 12 gastrointestinal stromal tumors, seven leiomyomas, and four schwannomas. Vs-med values for gastrointestinal stromal tumors, leiomyomas, and schwannomas were 2.46, 1.73, and 2.85 m/s, respectively, indicating that gastrointestinal stromal tumors and schwannomas were significantly stiffer than leiomyomas. VsN-med values for gastrointestinal stromal tumors, leiomyomas, and schwannomas were 40.5, 39, and 35.5%, respectively, with no significant differences. Endoscopic ultrasound-guided shear wave measurements are feasible for upper gastrointestinal subepithelial lesions and allow for the objective, non-invasive quantification of lesion stiffness. These results suggest the potential of endoscopic ultrasound-guided shear wave measurements as a valuable tool for the differential diagnosis of upper gastrointestinal subepithelial lesions.