Incidence of associated events during the performance of invasive procedures in healthy human volunteers

Muscle biopsy practices in the evaluation of neuromuscular disease: A systematic literature review

AIMS

Muscle biopsy techniques range from needle muscle biopsy (NMB) and conchotome biopsy to open surgical biopsy. It is unknown whether specific biopsy techniques offer superior diagnostic yield or differ in procedural complication rates. Therefore, we aimed to compare the diagnostic utility of NMB, conchotome and open muscle biopsies in the assessment of neuromuscular disorders.

METHODS

A systematic literature review of the EMBASE and Medline (Ovid) databases was performed to identify original, full-length research articles that described the muscle biopsy technique used to diagnose neuromuscular disease in both adult and paediatric patient populations. Studies of any design, excluding case reports, were eligible for inclusion. Data pertaining to biopsy technique, biopsy yield and procedural complications were extracted.

RESULTS

Sixty-four studies reporting the yield of a specific muscle biopsy technique and, or procedural complications were identified. Open surgical biopsies provided a larger tissue sample than any type of percutaneous muscle biopsy. Where anaesthetic details were reported, general anaesthesia was required in 60% of studies that reported open surgical biopsies. Percutaneous biopsies were most commonly performed under local anaesthesia and despite the smaller tissue yield, moderate- to large-gauge needle and conchotome muscle biopsies had an equivalent diagnostic utility to that of open surgical muscle biopsy. All types of muscle biopsy procedures were well tolerated with few adverse events and no scarring complications were reported with percutaneous sampling.

CONCLUSIONS

When a histological diagnosis of myopathy is required, moderate- to large-gauge NMB and the conchotome technique appear to have an equivalent diagnostic yield to that of an open surgical biopsy.

Tracing metabolic flux to assess optimal dietary protein and amino acid consumption

There is a general consensus that a dietary protein intake of 0.8 g protein/kg/day will prevent symptoms of protein deficiency in young, healthy individuals. However, individuals in many physiological circumstances may benefit from higher rates of dietary protein intake. Stable isotope tracer methodology enables a variety of approaches to assessing the optimal dietary protein intake in humans. In this paper, we present an overview of a variety of tracer methods, with a discussion of necessary assumptions, as well as the clinical circumstances in which different methods may be preferable. Although we discuss the nontracer method of nitrogen balance, which has historically been used to estimate dietary protein requirements, this paper primarily focuses on tracer methods for estimating dietary protein and essential amino acid requirements under different physiological conditions. We will explain the following approaches: isotopic measurement of urea production; the arterial-venous tracer balance method; measurement of the fractional synthetic and breakdown rates of muscle protein; the indicator and the direct amino acid oxidation methods; and different approaches to measuring whole-body protein synthesis and breakdown. The advantages and limitations of each method are discussed in the context of the optimal approaches for use under different circumstances.

Both clinical and practical considerations should inform how dietary protein intake is tracked in individuals. Little is known about optimal dietary protein intake in humans under different physiological conditions including disease states, prompting a review of current monitoring methods by Robert Wolfe at the University of Arkansas, Little Rock, USA, and co-workers. Monitoring nitrogen balance provides estimates of dietary protein and essential amino acid (EAA) levels, but requires several days of strict diet control. Various techniques monitor the uptake or fate of a specific tracer molecule in the body, but some are very invasive. The less invasive single EAA infusion methods provide rapid results and are valuable for monitoring immediate response to a meal, or in studies comparing protein intakes to a person’s baseline over time. Using two methods concurrently could improve accuracy of results.

The Skeletal Muscle Microbiopsy Method in Exercise and Sports Science Research: A Narrative and Methodological Review

BACKGROUND

The skeletal muscle microbiopsy protocol was introduced to the Exercise and Sports Science (ESS) research field in 1999 and has been used as a protocol to directly examine muscular structural and biochemical changes. There is much variation in the reporting of the microbiopsy protocol and its related pre-and post-procedure for participant care and sample collection. The purpose of this narrative and methodological review is to compare the microbiopsy to the traditional Bergström protocol used in the ESS field, identify and summarize all related microbiopsy protocols used in previous ESS studies and determine the most frequently used microbiopsy protocols aspects and associated pre- and post-biopsy procedures; METHODS: A review of literature up to January, 2022 was used following the PRISMA and Cochrane Methodological Review Guide to determine frequently used methods that may facilitate optimal and potential recommendations for muscle microbiopsy needle gauge (G), concentration or dose (% or mL) and administration of local anesthetic, co-axial/cannula introducer gauge (G), muscle depth (cm), muscle sample size collected (mg), passes to collect samples, time points of muscle sampling, and promotion of participant compliance and minimization of adverse events; RESULTS: 85 articles were selected based on the inclusionary requirements related to the ESS field or methodological considerations. The most frequently reported aspects in previous research to suggest the location of the vastus lateralis is the midpoint between the patella and the greater trochanter of the femur or 1/3 or 2/3 the distance from the patella to anterior superior iliac spine, 14 G biopsy needle, subcutaneous injected lidocaine administration (2 mL; 1%), 13 G co-axial/cannula, 1-2 cm muscle depth, 10-20 mg of muscle sample, ~3-time points, 2-3 passes; DISCUSSION: There is much variation in the reporting of the microbiopsy protocol and its related pre-and post-biopsy procedures. Standardization in reporting may promote recommendations to optimize data integrity, participant safety, participant adherence to the study design, and increase reproducibility. Recommendations are made for the microbiopsy procedure based on frequently reported characteristics.

In Vivo Visualization of Tissue Damage Induced by Percutaneous Muscle Biopsy via Novel High-Resolution MR Imaging

PURPOSE

Percutaneous muscle biopsy is the gold standard for tissue assessment in clinical practice and scientific studies. The aim of this study was to assess and quantify the ensuing tissue damage by in vivo magnetic resonance imaging (MRI).

METHODS

In this prospective study, we enrolled 22 healthy participants who underwent MRI of the thigh musculature about 1 wk after a percutaneous muscle biopsy of the vastus lateralis muscle. A total of 17 participants also volunteered for a second MR examination 2 wk after biopsy. Volumes of susceptibility-weighted imaging (SWI) lesions and muscle edema were assessed by SWI and T2-weighted MRI, respectively, after manual segmentation by two independent readers. For quantitative in vivo hematoma volume assessment, we additionally determined signal changes induced by experimental hematoma in an ex vivo model.

RESULTS

Mean overall volume of SWI lesions 1 wk after biopsy was 26.5 ± 21.7 μL, accompanied by a mean perifocal edema volume of 790.1 ± 591.4 μL. In participants who underwent two examinations, mean volume of SWI lesions slightly decreased from 29.8 ± 23.6 to 23.9 ± 16.8 μL within 1 wk (P = 0.13). Muscle edema volume decreased from 820.2 ± 632.4 to 359.6 ± 207.3 μL at the same time (P = 0.006). By calibration with the ex vivo findings, signal alterations on SWI corresponded to a blood volume of approximately 10-50 μL.

CONCLUSIONS

Intramuscular hematoma and accompanying muscle edema after percutaneous biopsy are small and decrease rapidly within the first 2 wk. These in vivo findings underline the limited invasiveness of the procedure.

Neurovascular structures in human vastus lateralis muscle and the ideal biopsy site

A density model of neurovascular structures was generated from 28 human vastus lateralis muscles isolated from embalmed cadavers. The intramuscular portion of arteries, veins, and nerves was dissected, traced on transparencies, and digitized before adjustment to an average muscle shape using Procrustes analysis to generate density distributions for the relative positions of these structures. The course of arteries, veins, and nerves was highly variable between individual muscles. Nevertheless, a zone of lower average neurovascular density was found between the tributaries from the lateral circumflex femoral and the deep femoral arteries. While the area with the lowest density was covered by the iliotibial tract and would therefore not be suitable for biopsies, another low-density area was located in the distal portion of vastus lateralis. This was just anterior to the iliotibial tract, in a zone that has been described as a good needle biopsy site. The reported complication rates of needle biopsies (0.1%-4%) are in the range of expectations when simulated based on this model. It is concluded that the optimal human vastus lateralis biopsy site is in the distal portion of the muscle, between ½ and ¾ of the length from the greater trochanter to the lateral epicondyle, just anterior to the iliotibial band.

Dudrick Research Symposium 2015-Lean Tissue and Protein in Health and Disease

The 2015 Dudrick Research Symposium "Lean Tissue and Protein in Health and Disease: Key Targets and Assessment Strategies" was held on February 16, 2015, at Clinical Nutrition Week in Long Beach, California. The Dudrick Symposium honors the many pivotal and innovative contributions to the development and advancement of parenteral nutrition made by Dr Stanley J. Dudrick, physician scientist, academic leader, and a founding member of the American Society for Parenteral and Enteral Nutrition. As the 2014 recipient of the Dudrick award, Dr Carrie Earthman chaired the symposium and was the first of 3 speakers, followed by Dr Robert Wolfe and Dr Steven Heymsfield. The symposium addressed the importance of lean tissue to health and response to disease and injury, as well as the many opportunities and challenges in its assessment at the bedside. Lean tissue assessment is beneficial to clinical care in chronic and acute care clinical settings, given the strong relationship between lean tissue and outcomes, including functional status. Currently available bioimpedance techniques, including the use of bioimpedance parameters, for lean tissue and nutrition status assessment were presented. The connection between protein requirements and lean tissue was discussed, highlighting the maintenance of lean tissue as one of the most important primary end points by which protein requirements can be estimated. The various tracer techniques to establish protein requirements were presented, emphasizing the importance of practical considerations in research protocols aimed to establish protein requirements. Ultrasound and other new and emerging technologies that may be used for lean tissue assessment were discussed, and areas for future research were highlighted.

Safety and feasibility of femoral catheters during physical rehabilitation in the intensive care unit

OBJECTIVE

Femoral catheters pose a potential barrier to early rehabilitation in the intensive care unit (ICU) due to concerns, such as catheter removal, local trauma, bleeding, and infection. We prospectively evaluated the feasibility and safety of physical therapy (PT) in ICU patients with femoral catheters.

DESIGN, SETTING, AND PATIENTS

We evaluated consecutive medical ICU patients who received PT with a femoral venous, arterial, or hemodialysis catheter(s) in situ.

MEASUREMENTS AND MAIN RESULTS

Of 1074 consecutive patients, 239 (22%) received a femoral catheter (81% venous, 29% arterial, 6% hemodialysis; some patients had >1 catheter). Of those, 101 (42%) received PT interventions, while the catheter was in situ, for a total of 253 sessions over 210 medical ICU (MICU) days. On these 210 MICU days, the highest daily activity level achieved was 49 (23%) standing or walking, 57 (27%) sitting, 25 (12%) supine cycle ergometry, and 79 (38%) in-bed exercises. During 253 PT sessions, there were no catheter-related adverse events giving a 0% event rate (95% upper confidence limit of 2.1% for venous catheters).

CONCLUSIONS

Physical therapy interventions in MICU patients with in situ femoral catheters appear to be feasible and safe. The presence of a femoral catheter should not automatically restrict ICU patients to bed rest.

The reliability of using the single-biopsy approach to assess basal muscle protein synthesis rates in vivo in humans

It has recently been proposed that basal muscle protein synthesis can be effectively assessed by measuring the background enrichment in total plasma protein, thereby omitting the initial biopsy, and determining the difference in enrichment from a single muscle biopsy obtained during a primed continuous infusion of isotope-labeled amino acids. We determined the reliability of calculating basal mixed muscle protein fractional synthetic rates (FSRs) from mixed plasma proteins and a single muscle biopsy compared against the sequential muscle biopsy approach. Ten men (age, 23 ± 1 years; body mass index, 22 ± 1 kg∙m(-2)) received muscle biopsies of the vastus lateralis after 2 and 4 hours of a primed continuous infusion of l-[ring-(13)C(6)]phenylalanine. Mixed muscle protein FSR was calculated from baseline plasma enrichments and muscle protein enrichments determined from the biopsy at 2 hours (1BX SHORT) or 4 hours (1BX LONG), or between muscle protein enrichments at 2 and 4 hours (2BX) of the infusion. No differences (P = .50) were observed in mixed muscle protein FSR, using plasma [ring-(13)C(6)]phenylalanine enrichments as the precursor, between the 1BX SHORT (0.031% ± 0.010%∙h(-1)), 1BX LONG (0.032% ± 0.007%∙h(-1)), or 2BX (0.035% ± 0.011%∙h(-1)) approach. A significant correlation was observed between the calculated muscle protein FSR assessed using the 1BX LONG and 2BX approach (r = 0.7, P = .02). Our data demonstrate that the single-biopsy approach, irrespective of whether the biopsy is obtained at 2 or 4 hours, can be used as a surrogate for the sequential-biopsy approach to determine basal muscle protein synthesis in a group.

Suction-modified Bergström muscle biopsy technique: experience with 13,500 procedures

INTRODUCTION

Bergström needle muscle biopsies have been used by exercise physiologists for over 35 years but have been less accepted by neuromuscular clinicians due to size concerns.

METHODS

We retrospectively reviewed over 13,500 muscle Bergström needle biopsies done over a 21-year period to determine sampling success, patient/subject experience, and complications. We compared sample yield between two different needles (Bergström vs. UCH), with and without suction modifications.

RESULTS

Needle biopsies adequate for histology and enzymology were obtainable from the vastus lateralis, deltoid, biceps brachii, soleus, and medial gastrocnemius muscles, with a success rate of >99.9% and a minor complication rate of 0.15%. Approximately 450 muscle fibers were submitted for histologic assessment; suction modification and use of the Bergström vs. UCH needle were associated with larger sample size (P < 0.05).

CONCLUSIONS

The suction-modified Bergström needle muscle biopsy technique is safe and provides an adequate sample size for histologic, ultrastructural, DNA, and enzyme analysis.

Repeated muscle biopsies through a single skin incision do not elicit muscle signaling, but IL-6 mRNA and STAT3 phosphorylation increase in injured muscle

To determine if muscle biopsies can be repeated using a single small (5-6 mm) skin incision without inducing immediate MAPK activation or inflammation in the noninjured areas, the phosphorylation of ERK1/2, p38-MAPK, c-Jun NH(2)-terminal kinases (JNKs), IκBα, IKKα, and signal transducer and activator of transcription 3 (STAT3) was examined concurrent with IL-6 mRNA in six muscle biopsies obtained from the vastus lateralis of five men. Four biopsies were obtained through the same incision (5-6 mm) from the right leg (taken at 0, 30, 123, and 126 min) and another two each from new incisions performed in the left leg (at 31 and 120 min), while the subjects rested supine. The first three biopsies from the right leg were taken ∼3 cm apart from prebiopsied areas. The last biopsy was obtained from the same point from which the second biopsy was sampled. The three biopsies performed through the same skin incision from noninjured muscle areas showed similar levels of ERK1/2, p38-MAPK, JNK, IKKα, IκBα, and STAT3 phosphorylation and similar IL-6 mRNA content. There were no significant differences in the levels of ERK1/2, p38-MAPK, JNK, IKKα, and IκBα phosphorylation between the mean of the three biopsies obtained from the same incision and the sixth biopsy obtained from an injured area. STAT3 phosphorylation was increased by ∼3.5-fold in the sixth biopsy compared with the mean the three biopsies obtained from the same incision (P < 0.05), and IL-6 mRNA content was increased by 1.8-fold (P < 0.05). In summary, repeated muscle biopsies can be performed through a single 5- to 6-mm skin incision without eliciting muscle signaling through cascades responding to cellular stress, inflammation, or muscle damage. STAT3 phosphorylation is an early event in the healing response to muscle injury, probably mediated by the autocrine production of IL-6.

Incidence of adverse events associated with percutaneous muscular biopsy among healthy and diseased subjects

The development of the percutaneous muscle biopsy technique is recognized as one of the most important scientific contributions in advancing our understanding of skeletal muscle physiology. However, a concern that this procedure may be associated with adverse events still exists. We reported the incidence of adverse outcomes associated with percutaneous muscle biopsy in healthy and diseased subjects. Medical records of 274 volunteers (496 muscle biopsies) were reviewed. This included 168 healthy subjects (330 muscle biopsies) as well as 106 chronically ill patients (166 muscle biopsies). This latter group encompassed patients with type II diabetes (n=28), osteoarthritis (n=39), inclusion body myositis (n=4), polymyositis (n=4), and chronic heart failure (n=31). The most common occurrences were pain (1.27%), erythema (1.27%), and ecchymosis (1.27%). Panic episode, bleeding, and edema were also reported (0.21%, 0.42%, and 0.84%, respectively), while infection, hematoma, inflammation, denervation, numbness, atrophy, and abnormal scarring were not verified. The percent of incidents did not differ between healthy and ill individuals. In conclusion, the incidence of complications associated with percutaneous muscle biopsy is scarce and of minor clinical relevance. Additionally, the rate of adverse events is comparable between healthy and chronically ill subjects.

Short-term effects of dietary fatty acids on muscle lipid composition and serum acylcarnitine profile in human subjects

In cultured cells, palmitic acid (PA) and oleic acid (OA) confer distinct metabolic effects, yet, unclear, is whether changes in dietary fat intake impact cellular fatty acid (FA) composition. We hypothesized that short-term increases in dietary PA or OA would result in corresponding changes in the FA composition of skeletal muscle diacylglycerol (DAG) and triacylglycerol (TAG) and/or the specific FA selected for β-oxidation. Healthy males (N = 12) and females (N = 12) ingested a low-PA diet for 7 days. After fasting measurements of the serum acylcarnitine (AC) profile, subjects were randomized to either high-PA (HI PA) or low-PA/high-OA (HI OA) diets. After 7 days, the fasting AC measurement was repeated and a muscle/fat biopsy obtained. FA composition of intramyocellular DAG and TAG and serum AC was measured. HI PA increased, whereas HI OA decreased, serum concentration of 16:0 AC (P < 0.001). HI OA increased 18:1 AC (P = 0.005). HI PA was associated with a higher PA/OA ratio in muscle DAG and TAG (DAG: 1.03 ± 0.24 vs. 0.46 ± 0.08, P = 0.04; TAG: 0.63 ± 0.07 vs. 0.41 ± 0.03, P = 0.01). The PA concentration in the adipose tissue DAG (µg/mg adipose tissue) was 0.17 ± 0.02 in those receiving the HI PA diet (n = 6), compared to 0.11 ± 0.02 in the HI OA group (n = 4) (P = 0.067). The relative PA concentration in muscle DAG and TAG and the serum palmitoylcarnitine concentration was higher in those fed the high-PA diet.

Thrombin injection for acute hemorrhage following angiography

Femoral arterial puncture is the main access for diagnostic and therapeutic intervention in vascular disease. Significant complications are unusual and include uncontrolled bleeding which usually requires surgery. We report the use of ultrasound-guided thrombin injection that prevented any immediate need for surgery in 2 cases of uncontrolled bleeding following femoral arteriography. Clinical presentations and treatment are reported, together with a review of the literature.