Limb Occlusion Research Articles

Fenestrated Anaconda Endograft for the Treatment of Complex Aortic Aneurysms: Systematic Review and Meta-Analysis.

To perform a systematic review and meta-analysis of the outcomes of Anaconda fenestrated endograft for the treatment of complex abdominal aortic aneurysms (cAAA). A systematic search of all the literature reported until May 2024 was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The pooled 30-day mortality rate, technical success rate, reintervention rate as well as bridging stent occlusion rate, and corresponding 95% confidence intervals (CIs) were estimated using fixed or random effect methods. A total of 526 study titles were identified by the initial search strategy, of which 6 were considered eligible for inclusion in the meta-analysis. A total of 782 patients (89% male) were identified among the eligible studies. The pooled 30-day mortality rate was 4.8% (95% CI, 3.5%-6.5%) while the reintervention rate was 7.9% (95% CI, 4.3%-14.1%) and 10.2% (95% CI, 5.8%-17.4%) in the early and late period, respectively. The pooled bridging stents occlusion was 2.7% (95% CI, 1.5%-4.9%) during 30 days and 3.5% (95% CI, 1.6%-7.6%) during follow-up. Overall technical success was 86.1% (95% CI, 62.9%-95.8%). The use of the Anaconda fenestrated endograft in treatment of complex aortic aneurysms involving the abdominal visceral vessels has low early and late mortality. Low rate of bridging stent occlusion occurs early postoperatively and during follow-up, mostly involving the renal arteries. Reinterventions during follow-up are mostly induced by limb occlusion. Lower early technical success rate is explained by the presence of a type Ia endoleak on final angiography, which however resolves spontaneously early postoperatively. The present systematic review and meta-analysis of observational studies provide evidence-based data regarding the safety and efficacy of the fenestrated Anaconda device for the primary treatment of cAAA in the perioperative period and at long-term follow-up. Six studies with an overall 782 patients were included. The technical success in patients with cAAA treated with Anaconda fenestrated endograft was 86% while the reintervention rate was 7.9% and 10.2 during the perioperative and long-term follow up period. The pooled 30-day occlusion rate for the bridging stents was 2.7% while the late pooled occlusion rate for the bridging stents among the studies was 3.5%. The use of the Anaconda fenestrated endograft in treatment of complex aortic aneurysms involving the abdominal visceral vessels seems feasible with promising outcomes. The lower early technical success is obscured by the presence of type Ia endoleak which, resolves spontaneously early postoperatively.

Impact of Antithrombotic Therapy on Thrombotic and Bleeding Complications after Elective Endovascular Repair of Abdominal Aortic Aneurysms.

To investigate the influence of antithrombotic therapy on occurrence of thrombotic and bleeding complications after endovascular aneurysm repair (EVAR). In this retrospective single-center cohort study, patients who underwent elective endovascular aneurysm repair for abdominal aortic aneurysm were categorized into three antithrombotic groups: single antiplatelet therapy (SAPT), anticoagulants, or dual antiplatelet therapy (DAPT). Outcome measures were the incidence of major adverse cardiovascular events (MACE), prosthetic limb occlusions, and bleeding complications during follow-up. Among 616 patients (SAPT: n = 450, anticoagulants: n = 84, and DAPT: n = 82), Kaplan-Meier analysis showed no significant difference (log-rank p = 0.37) in incidence of MACE between patients receiving SAPT (20.9%), anticoagulants (25.0%), and DAPT (14.6%) during a median follow-up of almost 4years. In multivariable Cox regression analysis, only age (HR = 1.03; 95% CI 1.01-1.06, p = 0.01) and American Society of Anesthesiologists (ASA) classification (HR = 1.46; 95% CI 1.12-1.91; p = 0.01) were significant predictors for MACE. Prosthetic limb occlusion was observed in 38 patients during a median follow-up of 4years; incidence between patients receiving SAPT (5.8%), anticoagulants (10.7%), and DAPT (3.7%) was not significantly different (log-rank p = 0.08). Age (HR = 0.96; 95% CI 0.92-1.00; p = 0.03) and use of anticoagulants (HR = 3.79, 95% CI 1.46-9.83; p < 0.01) were significant predictors for prosthetic limb occlusion. Bleeding complications occurred in 73 patients during median follow-up of almost 4years, without significant difference (log rank p = 0.06) in incidence between patients receiving SAPT (10.7%), anticoagulants (19.0%), and DAPT (11.0%). ASA classification (HR = 1.74; 95% CI 1.23-2.46; p < 0.01) was a significant predictor for bleeding complications. Use of anticoagulants after EVAR appears to be associated with a higher risk of prosthetic limb occlusion compared to the use of single or dual antiplatelet therapy.

Thromboembolic Complications After Treatment with the INCRAFT AAA Ultra-Low-Profile Stent Graft System.

Low-profile endografts have reported increased rates of limb graft occlusions. The INCRAFT stent graft system is an ultra-low profile endograft for the exclusion of infrarenal abdominal aortic aneurysms. Our aim was to report thromboembolic events (TE) in patients treated with the INCRAFT device and its association with risk factors. A retrospective study was performed of 80 patients treated with the INCRAFT endograft between February 2015 and December 2022 at a single institution. All available imaging studies were reviewed by two reviewers independently. TE included intraprosthetic thrombus (IPT), limb graft occlusion (LGO) and distal embolization. A regression analysis was performed to evaluate possible risk factors associated with the development of TE. These included tortuous access vessels, IPT, access vessel diameter and the ratio between the cross-sectional area of the mainbody to the bilateral limb grafts. Limb occlusions occurred in 7 patients (9%) and 12 limbs (7.5%) resulting in a primary and secondary patency at one, three and five years of 96% and 99%, 94% and 97% and 89% and 93%, respectively. IPT was found in 36% of patients and affected endograft limbs in 93%. Ten distal occlusions in 8 patients (10.0%) were considered to origin from IPT, which led to symptomatic occlusions of below-the-knee vessels in all patients. Freedom from IPT at one, three and five years was 80%, 61%, and 43%, respectively. Age ≤70 years and access vessel diameter ≥10 mm were associated with IPT development. IPT was significantly associated with LGO (OR 77.10, p=0.003). Thromboembolic events are frequent after treatment with the INCRAFT endograft with a limb graft occlusion rate of 9% per patient and IPT found in 36% of patients. IPT was more common in patients ≤70 years and was a significant risk factor for LGO.

Impact of exercise with blood flow restriction on muscle hypertrophy and performance outcomes in men and women.

Blood flow restriction training (BFRT) has been previously studied as an alternative form of resistance training to gain lean mass and improve performance outcomes. However, in all exercise studies of BFRT, the proportion of female participants represents only 17-29% of all research participants. This highlights a strong underrepresentation of females and the need for more knowledge on the impact of BFRT and sex differences. The primary objective was to compare the impact of 6-week BFRT on lean mass, strength, and performance outcomes between males and females. A total of 38 adults [age, 25.3 ± 3.1 years; female, n = 19 (50%)] performed whole-body resistance training program with blood flow restriction three times per week. Exercises were performed at 30% of 1-repetition maximum (1-RM) and blood flow restriction cuffs were set to 60% of each individual's limb occlusion pressure. Body composition was assessed via dual-energy x-ray absorptiometry and strength was measured using 1-RM. A significant increase in lean mass was observed in males (p = 0.009) and females (p = 0.023) with no difference in the change between groups (p = 0.279). Both males and females increased 1-RM for upper- and lower-body exercises, with significant interaction effects (time x sex) for chest press (p = 0.003), seated row (p = 0.038), knee flexion (p = 0.043), and knee extension (p = 0.035), suggesting males increased 1-RM more for these exercises. Furthermore, peak power was improved in males (p < 0.001) and females (p = 0.002) during a vertical squat jump, but a significant interaction (time x sex) effect was observed (p = 0.039), suggesting males increased to a greater extent. Males and females significantly increased lean body mass, to a similar degree, following six weeks of resistance training in combination with blood flow restriction. Likewise, both males and females improved muscle strength following 6-week BFRT, however males may improve strength to a greater extent than females.

Construction of tennis pose estimation and action recognition model based on improved ST-GCN

With the rapid growth of computer vision and deep learning technologies, the application of pose estimation and action recognition in sports training has become increasingly widespread. Due to factors such as complex movements, fast speed, and limb occlusion, pose estimation and action recognition in tennis face significant challenges. Therefore, this study first introduces selective dropout and pyramid region of interest pooling layer strategies in fast region convolutional neural networks. Secondly, a pose estimation algorithm based on multi-scale fusion pose residual network 50 is designed, and finally a spatiotemporal graph convolutional network model is constructed by fusing channel attention module and multi-scale dilated convolution module. The data showed that the average detection accuracy of the improved attitude residual network 50 was 70.4%, and the accuracy of object detection for small, medium, and large objects was 57.4%, 69.3%, and 79.2%, respectively. The continuous action recognition accuracy and inter action fluency detection time of the improved spatiotemporal graph convolutional network were 93.8% and 19.2 ms, respectively. When the sample size was 1000, its memory usage was 1378 MB and the running time was 32.7 ms. Experiments have shown that the improved model achieves high accuracy and robustness in tennis action recognition tasks, especially in complex scenes and limb occlusion conditions, where the model shows significant advantages. This study aims to provide an efficient and accurate motion recognition technology for tennis posture analysis and intelligent training.

Bare metal stent application to prevent limb occlusion in iliac arteries with severe tortuosity during an endovascular aneurysm repair: a cohort study.

The risk of limb graft occlusion (LGO) after endovascular aneurysm repair (EVAR) is increased by severe tortuosity of the iliac artery. A bare metal stent (BMS) may protect LGO, according to the hypothesis of this single-center retrospective analysis. All patients undergoing elective EVAR with a bifurcated stent graft between January 2012 and June 2022 were included in this cohort study. Patients demonstrating significant tortuosity at the iliac angle were incorporated into this study and classified into two groups: group A comprised those who received a BMS. In contrast, group B consisted of those who did not receive a BMS. The primary outcomes were the incidence of limb occlusion and technical success during the follow-up period. However, secondary outcomes included perioperative mortality, external iliac angioplasty, and crossed-limb techniques. This study has been reported as being in line with the STROCSS criteria. A total of 157 patients (mean age = 71.6 ± 8 years) with infrarenal abdominal aortic aneurysms were enrolled. In total, 50 individuals were included in group A, while 107 were in group B. Overall technical success was 100%, and only one (2%) patient from group A and 17 (15%) from group B suffered from limb occlusion during follow-up (p < 0.05). At a mean follow-up imaging duration of 28.7 ± 23.6 months (range 1-124), the estimated primary limb patency at 2 years was 98% for the BMS group and 84% for the non-BMS group (p < 0.05). There were no changes in perioperative mortality or crossed-limb procedures between the BMS and non-BMS groups. Nonetheless, there were disparities in external iliac angioplasty between the two groups during the follow-up period (p < 0.05). Deploying a BMS inside the iliac artery to prevent or treat limb occlusion is a safe and effective strategy, with clear prolonged outcomes concerning patency and re-interventions.

Acute Responses of Low-Load Resistance Exercise with Blood Flow Restriction.

Blood flow restriction (BFR) is a popular resistance exercise technique purported to increase metabolic stress and augment training adaptations over time. However, short-term use may lead to acute neuromuscular fatigue and higher exertion ratings. Objective: The purpose of the current study was to examine acute physiological responses to low-load resistance exercise utilizing BFR compared to higher-load, non-BFR resistance exercise. Methods: Recreationally trained males (n = 6) and females (n = 7) (mean ± standard deviation, age: 20 ± 1 yrs.; height: 172 ± 8 cm; weight: 73 ± 11 kg; BMI: 24.4 ± 2.2 kg·m-2; training experience: 4 ± 2 yrs.) had limb occlusion pressure determined (50%; right leg: 118 ± 11 mmHg; left leg: 121 ± 13 mmHg) using an automated, self-inflating cuff system during baseline testing. In subsequent sessions, using a randomized, cross-over design, participants completed one of two experimental conditions: (1) Low-load + BFR and (2) High load + non-BFR. In both conditions, participants completed one set of back squats at either 30% (BFR) or 60% (non-BFR) of an estimated 1RM for a max of 30 repetitions, followed by three additional sets with the same loads and a target of 15 repetitions per set. Blood lactate and countermovement jump (CMJ) height were measured pre- and post-back squat. Ratings of perceived exertion (RPE) were assessed following each set. Results: When collapsed across all sets, participants completed significantly more total repetitions in the BFR condition compared to non-BFR (75.0 ± 0.0 vs. 68.23 ± 9.27 reps; p = 0.015; ES: 1.03), but a lower training load volume (2380 ± 728 vs. 4756 ± 1538 kg; p < 0.001; ES: 1.97). There was a significant time-by-condition interaction (p < 0.001), with a greater increase in blood lactate occurring from baseline to post-back squat in the non-BFR condition (11.61 mmol/L, 95%CI: 9.93, 13.28 mmol/L) compared to BFR (5.98 mmol/L, 95%CI: 4.30, 7.65 mmol/L). There was another significant time-by-condition interaction (p = 0.043), with a greater reduction in CMJ occurring in the non-BFR condition (-6.01, 95%CI: -9.14, -2.88 cm; p < 0.001) compared to BFR (-1.50, 95%CI: -1.50, 4.51 cm; p = 0.312). Conclusions: Utilizing a low-load BFR protocol may allow for a higher training volume, yet lower metabolic stress and reduce neuromuscular fatigue compared to lifting at a higher load without the use of BFR.

Impact of limb occlusion pressure assessment position on performance, cardiovascular, and perceptual responses in blood flow restricted low-load resistance exercise: A randomized crossover trial

ABSTRACT This study investigated the effect of limb occlusion pressure (LOP) position on exercise performance, cardiovascular responses, and perceptual experiences during seated bilateral leg extensions with and without blood flow restriction (BFR). Thirty resistance-trained males (age: 22 ± 2 years; weight: 74.4 ± 13.6 kg; height: 177.4 ± 6.4 cm; BMI: 23.5 ± 3.3 kg/m2) participated. Each performed exercise to failure (4 sets, 30% 1RM, 1 min rest) in three conditions: Supine LOP-BFR, Seated LOP-BFR, and no-BFR. BFR was applied at 60% LOP. Significant interaction effects were found for RPE (p = 0.021, d = 0.76), RPD (p < 0.01, d = 1.72), and DOMS (p < 0.01, d = 2.28). Statistically significant fewer repetitions were completed in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.5), Seated LOP-BFR vs. no-BFR (p < 0.01, d = 1.0), and Seated LOP-BFR vs. Supine LOP-BFR (p < 0.01, d = 0.6). RPE was higher in Seated LOP-BFR vs. no-BFR (p < 0.01, d = 0.52). RPD was higher in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.62) and Seated LOP-BFR vs. no-BFR (p < 0.01, d = 1.25). DOMS was higher in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.77) and Seated LOP-BFR vs. no-BFR (p < 0.01, d = 3.52). Seated LOP-BFR increased perceptual demands and reduced repetitions compared to Supine LOP-BFR. Both LOP-BFR conditions reduced repetitions compared to no-BFR without affecting cardiovascular measures.

Low Profile Off the Shelf Multibranched Endografts for Urgent Endovascular Repair of Complex Aortic and Thoraco-abdominal Aneurysms in Patients with Hostile Iliac Access: European Multicentre Observational Study

The aim of the study was to report outcomes of a thoraco-abdominal, custom made, low profile (outer diameter 20 F) four branched endograft used as an off the shelf (OTS) solution for urgent juxta- and pararenal abdominal aortic aneurysms (JP-AAAs) and thoraco-abdominal aortic aneurysms (TAAAs) in the presence of hostile femoral or iliac access. Data for patients who underwent endovascular repair for urgent JP-AAAs and TAAAs with hostile femoral or iliac access by a low profile, four branched endograft in four European aortic centres between 2019 and 2023 were collected prospectively and analysed retrospectively. The investigated device was a custom made endograft with the configuration of a standard t-Branch, used as an OTS solution for urgent cases with hostile femoral or iliac access. Access related complications, spinal cord ischaemia (SCI), and 30 day death were assessed as primary outcomes. Survival, freedom from re-interventions (FFRs), and iliac limb occlusion (ILO) were evaluated as secondary outcomes. Fifty five cases were enrolled: ruptures, n= 14 (25%); symptomatic, n= 12 (22%); and asymptomatic TAAAs with diameter ≥ 80 mm, n= 29 (53%). There were seven (13%) JP-AAAs and 48 (87%) TAAAs. The median right and left external iliac artery diameters were 6.7 (interquartile range [IQR] 5.5, 7.9) mm and 7.1 (IQR 6.5, 8.7) mm, respectively. Bilateral hostile femoral or iliac access was reported in 39 patients (71%). Access related complications occurred in five cases (9%). There were four cases (7%) of SCI with two permanent paraplegias. Four patients (7%) died within 30 days. The median follow up was 22 (IQR 11, 33) months. Overall, eight patients (15%) required re-interventions: four within 30 days and four during follow up. No ILO occurred. Estimated one year FFRs and survival were 91% and 87%, respectively. Low profile OTS thoraco-abdominal endografts seems safe and effective to manage urgent JP-AAAs and TAAAs in the presence of hostile femoral or iliac access. Further larger studies with long term follow up are needed to validate this preliminary experience.

Low tourniquet pressure has less impact on lower extremity nerve innervation: comparison of different tourniquet pressures used with intraoperative neuromonitoring with a randomized controlled study

BackgroundWe aimed to investigate the compression and ischemic effects of two different tourniquet pressures on tissues during surgery show a clinical difference.MethodsPatients aged 18–65 years who underwent foot and ankle surgery and applied a tourniquet in a single center between September 2022 and November 2023 were included in this prospective randomized study. Accordingly, tourniquet pressures were applied as limb occlusion pressure (LOP) + 50 mmHg in group 1 (12 patients) and LOP + 100 mmHg in group 2 (12 patients). The time point at which the femoral nerve motor evoked potential (MEP) decreased by 50%, the time point at which the MEP decreased by 100% for all nerves (femoral, tibial, and deep peroneal), and the time point at which all responses returned after the tourniquet was deflated were identified as the time points for analysis.ResultsThere were no differences in demographic data (age, body mass index, and sex) between the two groups. The mean tourniquet pressure was 191 ± 16 mmHg in Group 1 and 247 ± 21 mmHg in Group 2 (p < 0.001). A 50% decrease in the femoral nerve MEP value was observed at an average of 47 min in Group 1 and 34 min in Group 2 (p < 0.001). A complete loss of MEP responses for all nerves was observed at an average of 69 min in Group 1 and 56 min in Group 2. After the tourniquet was deflated, all MEP responses returned to baseline values at an average of 8.5 min in Group 1 and 12.6 min in Group 2 (p = 0.007). The results showed that lower limb nerve innervation was affected later and returned to normal earlier after deflation of the tourniquet in Group 1 (low tourniquet pressure group).ConclusionsThe innervations of the lower extremity nerves were affected later in the group in which low tourniquet pressure was applied (average 191 mmHg). Again, in this group (LOP + 50 mmHg), nerve conduction recovered an average of 10 min after deflation and four minutes earlier than in the high tourniquet pressure group.Level of evidenceLevel I, diagnostic study.Trial registrationNCT05926154.

Custom-Made Device (CMD) for the Repair of Thoraco-Abdominal Aneurysm (TAA): Mid-Long Term Outcomes from a Single Southeast Asian Centre Experience in Singapore.

Introduction: Given the high risk of peri-operative morbidity and mortality associated with open repair, endovascular repair for thoraco-abdominal aneurysms is increasingly performed. This study aims to describe mid to long-term results for patients who were treated with COOK Custom-Made Endograft Device at a single Southeast Asian tertiary centre. Methods: Mid to long-term results of patients treated from 2012 to 2022 were retrospectively reviewed. Indications for treatment were aortic diameter > 5.5 cm, enlargement > 5 mm in 6 months or high-risk morphology. Clinical, operative, early to late complications and reintervention details were captured. The endpoints were technical success, primary patency and primary assisted patency. Results: Electronic medical records of 29 consecutive patients (64.4 ± 1.6 years old; 26/29 males 89.6%) were reviewed. 24/29 (83%) were hypertensive, and 20/29 (69%) were smokers. The mean diameter was 5.5 cm, and the majority were treated for Crawford type IV (19/29, 65.5%). Endograft deployment was 100%. Catheterisation of fenestration was successful in 109/116 (94%). 30-day mortality and morbidity were observed in 12/29 (41%), for which access site complications were most common. No significant haemorrhage or graft explant was recorded. The mean follow-up period was 32.4 months (range 1-108 months). Primary patency was 92.9% (95% CI: 83.8-100.0) at 6 months and decreased to 77.7% (95% CI: 63.4-95.2) at 24 months. Sac shrinkage or stability was noted in 17/29 (58.6%). Re-intervention was performed in 9/29 (31%) for limb occlusion (2/9, 22.2%), renal artery stent occlusion (1/9, 11.1%) and endoleaks (6/9, 66.6%). Assisted patency was maintained at 100% for 12 months before decreasing to 66.7% (95% CI: 37.9-100.0) at 24 months. Conclusions: The study reports the first mid-long-term result in this region, though limited by the sample size. Re-intervention at 30% suggests that disease and procedures remain challenging, emphasising the need to assimilate lessons and experience at high-volume centres.

The Effect of Low-Intensity Interval Exercise with Blood Flow Restriction on Plasma Cardiac Troponin: A Cross-Design Trial.

Low-intensity training with blood flow restriction (BFR) training could induce endurance adaptations, its impact on myocardial markers is still unclear compared to training without BFR. Consequently, the influence of low-intensity interval exercise with and without BFR and high-intensity interval exercise (HIIE) on cardiac troponin was determined in this study. Twelve physically active males between 18 and 26 years volunteered as participants. The participants completed 3 exercise tests in random order, which included 40% VO2max low-intensity cycling without BFR (group L), 40% VO2max low-intensity cycling with BFR set at 60% limb occlusion pressure (LOP) (group B), and 80% VO2max high-intensity cycling without BFR (group H). Participant muscle oxygen, blood flow, oxygen uptake, heart rate (HR), perceived exertion (RPE) rating, and pain levels were determined before and after exercise, after cuff inflation, and pre- and post-each exercise. Moreover, before each protocol, immediately after the exercises, and 3-4 hours after each exercise, elbow vein blood samples were collected to evaluate lactate (LA) and high-sensitivity cardiac troponin T (cTnT). Increased LA was recorded after exercise by the individuals in group H, which was more significant than in group B. Moreover, group B documented a more significant LA increment than group L (P < .05). The peak cTnT of groups B and H after exercise was significantly higher (P < .05). Furthermore, the increase was more significant than the values recorded by group L (P < .05). The present study demonstrated that low-intensity interval exercise combined with BFR could cause cTnT elevations compared to training without BFR. The increase was similar to HIIE protocols.

Implementation and Clinical Outcomes of Blood Flow Restriction Training on Adults With Cerebral Palsy: A Case Series.

Cerebral palsy (CP) is a congenital neurological disorder that causes musculoskeletal weakness and biomechanical dysfunctions. Strength training guidelines recommend at least 70% of 1-repetition maximum to increase muscle strength and mass. However, individuals with CP may not tolerate such high exercise intensity. Blood flow restriction (BFR) can induce similar gains in strength and muscle mass using loads as low as 20% to 30% 1-repetition maximum. This case series described the safety, feasibility, and acceptability of BFR in adults with CP and examined changes in muscle mass and strength. Three male participants with gross motor function classification system level 3 CP underwent strength training using a periodized 8-week BFR protocol. Outcomes included: Safety via blood pressure during and post-BFR exercises in addition to adverse event tracking; Feasibility via number of support people and time-duration of BFR exercises; Acceptability via rate of perceived discomfort (0-10) and qualitative interviews; Muscle Mass via ultrasonographic cross-sectional area of the quadriceps and hamstring; and Strength via (1) 3-repetition maximum in the leg press and knee extension, (2) isometric knee flexor and extensor muscle force measured with a hand-held dynamometer, and (3) 30-second sit-to-stand test. Participants replaced 2 exercises from their current regimen with seated knee extension and leg press exercises using progressively higher limb occlusion pressure and exercise intensity. Limb occlusion pressure started at 60%, by week 4 progressed to 80%, and then remained constant. The exercise repetition scheme progressed from fixed nonfailure repetition sets to failure-based repetition sets. Blood pressure never exceeded safety threshold, and no adverse events were reported. The BFR training was time-consuming and resource-intensive, but well-tolerated by participants (rate of perceived discomfort with a mean value of 5.8, 100% protocol adherence). Strength, as measured by 3-repetition maximum testing and 30-second sit-to-stand test, increased, but isometric muscle force and muscle mass changes were inconsistent. Blood flow restriction may be an effective means to increase strength in adults with CP who cannot tolerate high-intensity resistance training. Future research should compare BFR to traditional strength training and investigate mediators of strength changes in this population. for more insights from the authors (see the Video, Supplemental Digital Content available at: http://links.lww.com/JNPT/A473 ).

Comparison of Metabolic, Ionic, and Electrolyte Responses to Exhaustive Low-Load Strength Training With and Without Blood Flow Restriction and High-Load Resistance Training.

Low-load blood-flow-restriction resistance training (LL-BFR-RT) is gaining popularity, but its physiological effects remain unclear. This study aimed to compare LL-BFR-RT with low-load resistance exercise (LL-RT) and high-load resistance exercise (HL-RT) on metabolism, electrolytes, and ions in the lower extremities by invasive catheter measurements, which are crucial for risk assessment. Ten healthy men (27.6 ± 6.4 years) completed three trials of knee-extensor exercises with LL-RT (30% 1RM), LL-BFR-RT (30% 1RM, 50% limb occlusion pressure), and HL-RT (75% 1RM). The exercise protocol consisted of four sets to voluntary muscle failure with 1 min of rest between sets. Blood gas analysis was collected before, during, and after each trial through intravenous catheters at the exercising leg. LL-BFR-RT had lower total workload (1274 ± 237 kg, mean ± SD) compared to LL-RT (1745 ± 604 kg), and HL-RT (1847 ± 367 kg, p < 0.01), with no difference between LL-RT and HL-RT. Pain perception did not differ significantly. Exercise-induced drop in oxygen partial pressure, lactate accumulation and electrolyte shifts (with increased [K+]) occurred during under all conditions (p < 0.001). Creatine kinase and lactate dehydrogenase increased significantly 24- and 48-h postexercise under all three conditions (p < 0.001). This study, using invasive catheter measurements, found no significant differences in metabolic, ionic, and electrolyte responses among LL-BFR-RT, LL-RT, and HL-RT when exercised to voluntary muscular failure. LL-BFR-RT reduced time to failure without specific physiological responses.

Blood flow restriction: The acute effects of body tilting and reduced gravity analogues on limb occlusion pressure.

Blood flow restriction (BFR) has been identified as a potential countermeasure to mitigate physiological deconditioning during spaceflight. Guidelines recommend that tourniquet pressure be prescribed relative to limb occlusion pressure (LOP); however, it is unclear whether body tilting or reduced gravity analogues influence LOP. We examined LOP at the leg and arm during supine bedrest and bodyweight suspension (BWS) at 6° head-down tilt (HDT), horizontal (0°), and 9.5° head-up tilt (HUT) positions. Twenty-seven adults (age, 26±5 years; height, 1.75±0.08m; body mass, 73±12kg) completed all tilts during bedrest. A subgroup (n=15) additionally completed the tilts during BWS. In each position, LOP was measured twice in the leg and arm using the Delfi Personalized Tourniquet System after 5 min of rest and again after a further 5 min. The LOP at the leg increased significantly from 6° HDT to 9.5° HUT in bedrest and BWS by 9-15mmHg (Cohen's d=0.7-1.0). Leg LOP was significantly higher during BWS at horizontal and 9.5° HUT postures relative to the same angles during bedrest by 8mmHg (Cohen's d=0.6). Arm LOP remained unchanged between body tilts and analogues. Intraclass correlation coefficients for LOP measurements taken after an initial and subsequent 5min rest period in all conditions ranged between 0.91-0.95 (leg) and 0.83-0.96 (arm). It is advised that LOP be measured before the application of a vascular occlusion in the same body tilt/setting to which it is applied to minimize discrepancies between the actual and prescribed tourniquet pressure.

Exploring immediate cardiorespiratory responses: low-intensity blood flow restricted cycling vs. moderate-intensity traditional exercise in a randomized crossover trial

PurposeBlood-flow restriction (BFR) endurance training may increase endurance performance and muscle strength similar to traditional endurance training while requiring a lower training intensity. We aimed to compare acute cardiorespiratory responses to low-intensity interval exercise under BFR with moderate-intensity traditional interval exercise (TRA).MethodsWe conducted a randomized crossover study. The protocol involved three cycling intervals interspersed with 1 min resting periods. With a 48-h washout period, individuals performed the protocol twice in random order: once as BFR-50 (i.e., 50% incremental peak power output [IPPO] and 50% limb occlusion pressure [LOP]) and once as TRA-65 (65% IPPO without occlusion). TRA-65 intervals lasted 2 min, and time-matched BFR-50 lasted 2 min and 18 s. Respiratory parameters were collected by breath-by-breath analysis. The ratings of perceived breathing and leg exertion (RPE, 0 to 10) were assessed. Linear mixed models were used for analysis.ResultsOut of the 28 participants initially enrolled in the study, 24 healthy individuals (18 males and 6 females) completed both measurements. Compared with TRA-65, BFR-50 elicited lower minute ventilation (VE, primary outcome) (-3.1 l/min [-4.4 to -1.7]), oxygen consumption (-0.22 l/min [-0.28 to -0.16]), carbon dioxide production (-0.25 l/min [-0.29 to -0.20]) and RPE breathing (-0.9 [-1.2 to -0.6]). RPE leg was significantly greater in the BFR-50 group (1.3 [1.0 to 1.7]).ConclusionBFR endurance exercise at 50% IPPO and 50% LOP resulted in lower cardiorespiratory work and perceived breathing effort compared to TRA at 65% IPPO. BFR-50 could be an attractive alternative for TRA-65, eliciting less respiratory work and perceived breathing effort while augmenting perceived leg muscle effort.Trial registrationNCT05163600; December 20, 2021.

Fate assessment of the ectatic common iliac artery using flared limb during endovascular aneurysm repair.

This study aimed to evaluate the outcomes and anatomical predictors of the complications of flared limb (FL) use for ectatic common iliac arteries accompanied by abdominal aortic aneurysm treated with endovascular aneurysm repair (EVAR). In this single-center retrospective study, we reviewed data from 391 patients (638 limbs) treated between 2005 and 2020. The cohort was divided into two groups. The standard limbs (SLs, n = 403) included stent graft (SG) of <20mm in diameter and the FLs (n = 235) included stent graft of ≥20mm in diameter. Complications within 30days were investigated as the short-term outcome. Limb events during follow-up including type Ib endoleak (EL), type IIIa EL, and limb occlusion were compared between SLs and FLs using log-rank test. Early results indicated that the FL group had a significantly higher incidence of intraoperative type Ib EL at 5.1% (12), than 1.7% (7) in the SLs (p = .016). For 19 patients in whom intraoperative type Ib EL was discovered, SG extension alone or internal iliac artery embolization was all performed before completing the procedure. Overall, we noted one case of type Ib EL and two cases of limb events in each group at 30 days. Over a median follow-up of 39months, 31 (4.9%) events (17 type Ib EL, 2 type IIIa EL, and 12 limb events), 13 (5.5%) in FLs and 18 (4.5%) in SLs (p = .984), were observed. The FLs had significantly higher rates of aortic sac enlargement, with 46 (19.6%) cases for FLs and 36 (8.9%) for SLs (p < .001). The Kaplan-Meier analysis revealed significant differences at 5years in SLs versus FLs for freedom from type Ib EL (96.6% vs 82.4%, respectively; p < .001) and no difference in freedom from limb events (94.7% vs 84.5%, respectively; p = .519). Furthermore, no difference was observed for overall survival and aneurysm-related mortality. Although an FL for EVAR is used to treat dilated iliac arteries, there is an increased risk of intraoperative and late type Ib EL and aortic sac enlargement. Long-term close follow-up is mandatory, especially in the patients who undergo EVAR using FLs.

Low-Load Resistance Exercise With Blood Flow Restriction Versus High-Load Resistance Exercise on Hamstring Muscle Adaptations in Recreationally Trained Men.

Kamiş, O, Gürses, VV, Şendur, HN, Altunsoy, M, Pekel, HA, Yıldırım, E, and Aydos, L. Low-load resistance exercise with blood flow restriction vs. high-load resistance exercise on hamstring muscle adaptations in recreationally trained men. J Strength Cond Res XX(X): 000-000, 2024-Low-load resistance exercise with blood flow restriction (BFR-RE) has been suggested as a viable alternative exercise for traditional high-load resistance exercise (HL-RE). However, very little is known about hamstring muscle thickness, stiffness, and strength after BFR-RE. This study aimed to compare the effects of 6 weeks of BFR-RE and HL-RE on hamstring muscle thickness, stiffness, and strength. Twenty-nine recreationally trained men were pair matched and randomly assigned to the BFR-RE (n = 15) and HL-RE (n = 14) groups. The BFR-RE groups performed bilateral lying leg curl exercise (30-15-15-15 reps, 30-second rest between the sets, 30% 1RM) with BFR cuffs (60% of limb occlusion pressure), whereas HL-RE performed the same exercise (3 × 12 reps, 90-second rest between the sets, 70% 1RM) without BFR cuffs. Hamstring muscle thickness, muscle stiffness, isokinetic muscle strength, and 1RM were assessed at baseline and follow-up after completing a 6-week resistance exercise program (3× a week). Hamstring muscle thickness was assessed by ultrasonography, whereas muscle stiffness was evaluated by shear wave elastography. Isokinetic dynamometry and a 1RM strength test were used to determine muscular strength before and after the exercise program. Statistical significance was set at p < 0.05. No significant effect was found for hamstring muscle strength, thickness, and stiffness for group and group × time interaction, and only a significant main effect of time (p < 0.001) was observed for all outcomes. Both groups experienced significant improvements for all outcomes from baseline to follow-up without any between-group differences. In conclusion, results revealed that BFR-RE can provide similar hamstring muscle strength, thickness, and stiffness compared with HL-RE.

Hypoalgesia and Conditioned Pain Modulation in Blood Flow Restriction Resistance Exercise.

We compared the magnitude of exercise-induced hypoalgesia and conditioned pain modulation between blood-flow restriction (BFR) resistance exercise (RE) and moderate-intensity RE. Twenty-five asymptomatic participants performed unilateral leg press in two visits. For moderate-intensity RE, subjects exercised at 50% 1RM without BFR, whereas BFR RE exercised at 30% 1RM with a cuff inflated to 60% limb occlusion pressure. Exercise-induced hypoalgesia was quantified by pressure pain threshold changes before and after RE. Conditioned pain modulation was tested using cold water as the conditioning stimulus and mechanical pressure as the test stimulus and quantified as pressure pain threshold change. Difference in conditioned pain modulation pre- to post-RE was then calculated. The differences of RE on pain modulations were compared using paired t-tests. Pearson's r was used to examine the correlation between exercise-induced hypoalgesia and changes in conditioned pain modulation. We found greater hypoalgesia with BFR RE compared to moderate-intensity RE (p=0.008). Significant moderate correlations were found between exercise-induced hypoalgesia and changes in conditioned pain modulation (BFR: r=0.63, moderate-intensity: r=0.72). BFR RE has favorable effects on pain modulation in healthy adults and the magnitude of exercise-induced hypoalgesia is positively correlated with conditioned pain modulation activation.

Comparison of the systolic blood pressure and limb occlusion pressure methods in determining effective tourniquet pressure in upper limb surgeries

Introduction: The importance of a tourniquet to a surgeon cannot be overemphasised. Pneumatic tourniquet pressure is usually determined by systolic blood pressure (SBP), but a new emerging method, the limb occlusion pressure (LOP) appears more promising, especially in upper limb surgeries. We compare the effectiveness of the SBP and LOP methods in determining the tourniquet pressure in forearm bone surgeries. Material and Methods: This study was a prospective comparative study involving 60 forearm bone surgeries conducted over a 1-year period with randomisation into two groups. Those whose tourniquet pressure was determined using the SBP method (Group A) and those whose pressure was determined using the LOP method (Group B). Data collected included the tourniquet pressure, tourniquet performance using a Likert scale as well as tourniquet-related complications were noted. Analysis was done with the Statistical Package for the Social Sciences (version 22 trademark of the International Business Machine) and Excel (version 13.0, Microsoft, Redmond, WA). Results: There was a statistically significant difference in the mean tourniquet pressure between the two groups (SBP = 234.43 ± 11.87 mmHg; LOP = 199.17 ± 16.44 mmHg, P &lt; 0.001). Both methods provided a satisfactory dry field throughout the tourniquet duration with no statistically significant difference in the tourniquet performance between the two groups. Although two cases of tourniquet-related nerve palsy were noted in the SBP group, it was not statistically significant (P = 0.355). Conclusion: The LOP method provided a satisfactory dry surgical field at a lower tourniquet pressure than the SBP method with no complications.