We aimed to establish the prevalence of the musculocutaneous nerve (MCN) variations and the probability of the variation being pure or mixed in the same plexus. We applied the principles of evidence-based anatomy to find, appraise, and synthesize data through a meta-analysis of anatomical studies. The variations were grouped based on the presence and location of the communicating branch with the median nerve and the origin of branches to anterior arm muscles. Forty-three cadaveric studies met the inclusion criteria, providing data from 4124 plexuses. The overall pooled prevalence of plexuses with MCN variations was 20%. Based on the classification applied in our study, the pooled prevalence of variations was 17% in region 1A, 20% in region 1B, 36% in region 2 and 49% in region 3. Importantly, 64.58% of variations in region 1A and 74.14% of variations in region 1B were mixed, that is, associated with a variation in another region. The odds of finding another variation in the presence of a variation in region 2 or 3 were equal 0.37 and 0.52, respectively, demonstrating a significantly lower probability of finding mixed variations involving these regions, when compared with region 1A. Variations of the MCN are most common in the part distal to the exit from within or beneath the coracobrachialis muscle. Proximal variations are more often associated with another variation located along the nerve. These findings can assist health care professionals in the treatment of brachial plexus lesions. Clin. Anat., 2018. © 2018 Wiley Periodicals, Inc.

Aims The aim of our study was to assess the clinical significance of the exercise stress testing endpoints, namely 85% of maximal theoretical heart rate (MTHR), metabolic equivalent of task, and rating of perceived exertion (RPE), and their relation to electrocardiographic (ECG) changes in a healthy adult population. Methods A cross-sectional study was conducted on 408 males and 52 females (mean age 39.4 ± 8.6 years) who performed the maximal cycle ergometer exercise stress test until volitional exhaustion, reporting the RPE score at 85% of MTHR and at peak exercise. Metabolic equivalents of task were indirectly calculated from the maximum workload and compared with the predicted values. Sitting torso-lead ECG and blood pressure were recorded at rest, during exercise and during recovery. Results Of 460 participants, 73% exceeded 85% of MTHR. The RPE score represented the overall most significant endpoint of exercise stress testing, with the median value of 17 at peak exercise. ECG events were detected in 23/124 (18.5%) who reached ≤ 85% of MTHR and in 61/336 (18.2%) who achieved >85% of MTHR ( p = 0.92). In the latter group, 54% of ECG changes occurred at < 85% of MTHR and 46% at > 85% of MTHR ( p = 0.51). If the exercise stress testing had been interrupted at ≤ 85% of MTHR, almost half of the ECG events would have remained undetected and 35% of the cardiovascular abnormalities observed at the diagnostic follow-up would have remained undiagnosed. Conclusion Terminating exercise stress testing before volitional exhaustion and an RPE score of 17 limits the test accuracy and reduces the possibility to detect cardiovascular abnormalities in apparently healthy adult populations.

Introduction Sleeve gastrectomy (SG) has become a widespread treatment option in patients affected by severe obesity. However, studies investigating the impact of the subsequent weight loss on the ventilatory response at rest and during physical exercise are lacking. Methods This is an observational study on 46 patients with severe obesity (76% females), comparing parameters of ventilatory function 1 month before and 6 months after SG. Patients were first evaluated by resting spirometry and subsequently with an incremental, maximal cardiopulmonary exercise test (CPET) on treadmill. Results The important weight loss of 26.35 ± 6.17% of body weight (BMI from 43.59 ± 5.30 to 32.27 ± 4.84 kg/m2) after SG was associated with a significant improvement in lung volumes and flows during forced expiration at rest, while resting ventilation and tidal volume were reduced (all p ≤ 0.001). CPET revealed decreased ventilation during incremental exercise (p < 0.001), with a less shallow ventilatory pattern shown by a lower increase of breathing frequency (∆BFrest to ATp = 0.028) and a larger response of tidal volume (∆TVAT to Peakp < 0.001). Furthermore, a concomitant improvement of the calculated dead space ventilation, VE/VCO2 slope and peripheral oxygen saturation was shown (all p ≤ 0.002). Additionally, the increased breathing reserve at peak exercise was associated with a lower absolute oxygen consumption but improved exercise capacity and tolerance (all p < 0.001). Conclusion The weight loss induced by SG led to less burdensome restrictive limitations of the respiratory system and to a reduction of ventilation at rest and during exercise, possibly explained by an increased ventilatory efficiency and a decrease in oxygen demands.

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