Ultrasound guided compressibility of the lower leg anterior tibial muscle compartment: a feasibility study.

OBJECTIVES: Some young individuals participating in sports activities may encounter lower leg muscle pain and tightness, potentially indicating chronic exertional compartment syndrome (CECS). While muscle pressure measurement is typically recommended for diagnosis, it is invasive and associated with low sensitivity and specificity. Thus, there is a need for novel diagnostic approaches. METHODS: This feasibility study aims to assess whether an ultrasound-guided technique can effectively measure the compressibility of the anterior tibial muscle compartment, focusing on optimal leg positioning and identifying reliable external and internal anatomical landmarks. The compressibility of the anterior tibial muscle compartment was evaluated using ultrasound images obtained at 10 mmHg and 80 mmHg external pressure, with the drop in compartment thickness used to calculate the compressibility ratio. Measurements were conducted in various leg positions and utilizing different external and internal landmarks. RESULTS: Studies in healthy volunteers showed that knee and heel support positioning, measuring at the leg's widest circumference, and using the interosseous membrane as an internal landmark yielded the lowest measurement variability with an intra class correlation of .977 (.764-1.000; 95%-confidence interval). CONCLUSION: These findings suggest that ultrasound-guided techniques can feasibly determine the compressibility ratio of the anterior tibial muscle compartment, providing valuable insights for standardized protocols in future studies on suspected cases of chronic exertional compartment syndrome.

Lidocaine patch as noninvasive alternative treatment option in children with anterior cutaneous nerve entrapment syndrome: A retrospective case series.

BACKGROUND: Chronic abdominal pain in children is occasionally caused by anterior cutaneous nerve entrapment syndrome (ACNES). Diagnosing and treating this typical peripheral abdominal wall neuropathy is challenging. Management usually starts with minimally invasive tender point injections. Nevertheless, these injections can be burdensome and might even be refused by children or their parents. However, a surgical neurectomy is far more invasive. Treatment with a Lidocaine 5% medicated patch is successfully used in a variety of peripheral neuropathies. AIMS: This single center retrospective case series aimed to evaluate the effectiveness and tolerability of lidocaine patches in children with ACNES. METHODS: Children aged under 18 diagnosed with ACNES who were treated with a 10 day lidocaine patch treatment between December 2021 and December 2022 were studied. Patient record files were used to collect treatment outcomes including pain reduction based on NRS and complications. RESULTS: Twelve of sixteen children (mean age 13 years; F:M ratio 3:1) diagnosed with ACNES started the lidocaine patch treatment. Two patients achieved a pain free status and remained pain free during a 4 and 7 months follow-up. A third child reported a lasting pain reduction, but discontinued treatment due to a temporary local skin rash. Five additional patients reported pain reduction only during application of the patch. The remaining four children experienced no pain relief. No adverse effects were reported. CONCLUSION: Lidocaine patches provides pain relief in a substantial portion of children with ACNES.

Pulsed radiofrequency or surgery for anterior cutaneous nerve entrapment syndrome: Long-term results of a randomized controlled trial.

PURPOSE: Patients with anterior cutaneous nerve entrapment syndrome (ACNES) often require a step-up treatment strategy including abdominal wall injections, pulsed radiofrequency (PRF) or a neurectomy. Long-term success rates of PRF and surgery are largely unknown. The aim of the current study was to report on the long-term efficacy of PRF and neurectomy in ACNES patients who earlier participated in the randomized controlled PULSE trial. METHODS: Patients who completed the PULSE trial were contacted about pain status and additional treatments in the following years. Treatment success was based on numerical rating scale (NRS) following IMMPACT recommendations and Patient Global Impression of Change (PGIC) scores. RESULTS: A total of 44 of the original 60 patients were eligible for analysis (73.3%). Median follow-up was 71.5 months. One patient (4.3%) was still free of pain after a single PRF session, and five additional patients (21.7%) were free of pain by repetitive PRF treatments. By contrast, 13 patients (61.9%) in the neurectomy group were still free of pain without additional treatments. All pain recurrences and therefore primary re-interventions occurred in the first 2 years after the initial treatment. CONCLUSION: Approximately one in five ACNES patients undergoing PRF treatment reports long-term success obviating the need of surgical intervention. Surgery for ACNES is long-term effective in approximately two of three operated patients. Recurrent ACNES beyond 2 years after either intervention is rare.

Visceral symptoms in patients with anterior cutaneous nerve entrapment syndrome (ACNES): expression of viscerosomatic reflexes?

PURPOSE: Anterior cutaneous nerve entrapment (ACNES) is characterized by neuropathic pain in a predictable, circumscript abdominal area. The diagnostic delay is long, with half of ACNES-affected individuals reporting nausea, bloating, or loss of appetite mimicking visceral disease. The aim of this study was to describe these phenomena and to determine whether treatment could successfully reverse the visceral symptoms. METHODS: This prospective observational study was conducted between July 2017 and December 2020 at SolviMáx, Center of Excellence for Chronic Abdominal Wall and Groin Pain, Máxima Medical Center, Eindhoven. Adult patients who fulfilled published criteria for ACNES and reported at least one visceral symptom at intake were eligible for the study. A self-developed Visceral Complaints ACNES Score (VICAS) questionnaire that scores several visceral symptoms (minimum 1 point, maximum 9 points) was completed before and after therapy. The success of treatment was defined as at least 50% reduction in pain. RESULTS: Data from 100 selected patients (86 females) aged 39 ± 5 years were available for analysis. Frequently reported symptoms were abdominal bloating (78%), nausea (66%) and altered defecation (50%). Successful treatment significantly reduced the number of visceral symptoms, with a VICAS before of 3 (range 1-8) and after of 1 (range 0-6) (p < 0.001). A low baseline VICAS was associated with successful treatment outcome (OR 0.738, 95% CI 0.546-0.999). CONCLUSION: Patients with ACNES may report a variety of visceral symptoms. Successful treatment substantially reduces these visceral symptoms in selected patients.

Lower Leg Lateral Chronic Exertional Compartment Syndrome: Prospective Surgical Treatment Outcomes for Isolated or Combined Lateral Fasciotomy.

BACKGROUND: Chronic exertional compartment syndrome involving the lower leg lateral compartment (lat-CECS) seldom occurs isolated but is usually combined with CECS of the anterior (ant-CECS) or deep posterior compartment (dp-CECS). Patient characteristics in lat-CECS and outcome after surgery are largely unknown. The aim of this prospective case series was to describe patient characteristics and symptoms and to report on outcome following a fasciotomy. METHODS: All patients diagnosed with lat-CECS based on exertional lateral lower leg symptoms and elevated intracompartmental pressure (ICP) measurements according to the Pedowitz criteria (ICP ≥ 15 mm Hg at rest, and/or ≥30 mm Hg after 1 minute, and/or ≥20 mm Hg 5 minutes after exercise) were eligible for this study. A standard intake questionnaire scoring symptom patterns was completed by all patients. Patients who were operated for lat-CECS were asked to complete a 3-month and 12-month postoperative questionnaire scoring symptoms and surgical outcome. Patients with a history of CECS surgery, recent lower leg trauma, or peripheral neurovascular disease were excluded. RESULTS: A total of 881 patients with possible lower leg CECS completed an intake questionnaire and 88 (10%) were diagnosed with lat-CECS according to the Pedowitz criteria (isolated lat-CECS n = 10; lat/ant CECS n = 54, lat/ant/dp CECS n = 19, lat/dp CECS n = 5). Severe pain during exercise and moderate tightness during rest were frequently reported. A group of 28 patients (49 legs; isolated lat-CECS n = 2; lat/ant CECS n = 22, lat/ant/dp CECS n = 3, lat/dp CECS n = 1) was analyzed after fasciotomy. Complications were minor (wound infection requiring antibiotics, n = 3; temporary complex regional pain syndrome with spontaneous recovery, n = 1). Superficial peroneal nerve damage was not observed. One year after surgery, 64% rated outcome as excellent or good, whereas 71% had resumed sports activities. CONCLUSION: One in 10 patients with anterolateral exertional lower leg pain evaluated in a tertiary referral center met diagnostic criteria for lat-CECS. Pain and tightness were present during exertion and were often reported occurring during rest and at night. In this series, we found fasciotomy-either an isolated (lateral) or a multiple (combined with anterior and/or deep posterior) compartment fasciotomy-is safe and beneficial in most patients. LEVEL OF EVIDENCE: Level IV, case series.

Reliability of 2D video analysis assessing running kinematic variables in patients with exercise-related leg pain in a primary care practice.

BACKGROUND: Suboptimal lower limb and trunk positionings is known to influence exercise-related leg pain (ERLP). It is unknown whether simple 2D video analysis is useful for recording and interpreting running variables in a primary care practice. RESEARCH QUESTION: Is 2D video analysis a reliable instrument to assess running variables in patients with ERLP in a primary care practice? METHODS: Participants undergoing an evaluation for ERLP in two primary care practices were studied. In this reliability study, analysis of running variables was performed by 4 blinded raters on one-stride videos captured with non-high speed cameras (30 fps). Intraclass correlation coefficients (two-way random; ICC 2,1) were calculated to determine the inter-rater reliability. The intra-rater reliability was presented by ICC type two-way mixed (3,1). Footstrike pattern was analyzed by calculating the Fleiss' kappa for inter-rater agreement and Cohen's kappa for intra-rater agreement. Sample size calculation indicated that 16 participants would be required for answering the research question. RESULTS: Data of all 16 participants (9 males, age 31 ± 10 yr) were of sufficient quality for analysis. The 2D video analysis demonstrated excellent inter-rater reliability with an overall ICC value of 0.999 (95 % CI = 0.998-0.999). The ICC value of the eversion was 0.384 (95 % CI = 0.148-0.66) and after correction of the systematic error, 0.817 (95 % CI = 0.664-0.922). The agreement on footstrike was substantial with a Fleiss kappa of 0.737. The overall intra-rater reliability was excellent with an ICC value of 0.997 (95 % CI = 0.996-0.997). The intra-rater agreement of the footstrike was excellent with a Cohen's kappa of 0.868. SIGNIFICANCE: 2D video analysis provides a highly reliable, relative inexpensive, feasible and suitable measuring instrument for determining running variables in patients ERLP in a primary care setting. This simple technique may identify possible running variables associated with different types of ERLP and may serve as an instrument for tailor-made gait retraining programs.

The Scratch Collapse Test in patients diagnosed with Anterior Cutaneous Nerve Entrapment Syndrome (ACNES): A report of three cases.

INTRODUCTION AND IMPORTANCE: The Scratch Collapse Test (SCT) is currently used as a supportive tool diagnosing peripheral nerve neuropathies including carpal tunnel syndrome or peroneal nerve entrapment. Some patients with chronic abdominal pain suffer from entrapment of terminal branches of intercostal nerves (anterior cutaneous nerve entrapment syndrome, ACNES). ACNES is characterized by a severe disabling pain at a predictable area of the anterior abdomen. Clinical examination shows altered skin sensation and painful pinching at the area of pain. However, these findings may be subjective. CASE PRESENTATION: In three female patients aged 71, 33, and 43 years with suspected ACNES, the SCT was positive when scratching over the skin of the affected nerve-ending at the abdominal wall. The diagnosis ACNES was confirmed with a local abdominal wall infiltration at the tenderpoint in all three patients. In case three, the SCT turned negative after lidocaine infiltration. CLINICAL DISCUSSION: ACNES was hitherto a clinical diagnosis just based on clues in medical history and physical examination. Performing a SCT in patients possibly having ACNES may additionally contribute to the diagnosis. CONCLUSION: The SCT may serve as an additional tool for diagnosing patients with possible ACNES. A positive SCT in patients with ACNES supports the hypothesis that ACNES is indeed a peripheral neuropathy of terminal branches of the lower thoracic intercostal nerves. Controlled research is necessary to confirm the role of a SCT in ACNES.

Short- and long-term outcomes after endarterectomy with autologous patching in endurance athletes with iliac artery endofibrosis.

OBJECTIVE: Endurance athletes such as cyclists may develop intermittent claudication owing to iliac artery endofibrosis after long-lasting extreme hemodynamic challenges. This study investigated short-term (<1.5 years) and long-term (>5 years) satisfaction and safety after a surgical endarterectomy and autologous patching. METHODS: Data of endurance athletes who underwent an endarterectomy for flow limitation of the iliac artery owing to endofibrosis between 1997 and 2015 in one center were studied. Maximal cycling exercise tests, ankle-brachial index with flexed hips, echo-Doppler examination (peak systolic velocity), and contrast-enhanced magnetic resonance angiography were performed before and 6 to 18 months after surgery. Short-term and long-term satisfaction were evaluated using questionnaires. Potential patch dilatation was assessed using echo-Doppler. RESULTS: Analysis of 68 patients (79 legs; 55.7% males, median age at the time of surgery, 34 years; interquartile range, 26-41 years) demonstrated that cycling workload at symptom onset improved from 226 ± 97 to 333 ± 101 (P < .001) Watts. Peak workload increased from 326 ± 111 to 352 ± 93 Watts (P < .001). Ankle-brachial index with flexed hips increased from 0.34 (interquartile range [IQR], 0.00-0.47) to 0.59 (IQR, 0.51-0.69; P < .001). Peak systolic velocity with extended and flexed hip decreased from 2.04 m·sec-1 (IQR, 1.52-2.56 m·3sec-1) to 1.25 m·sec-1 (IQR, 0.92-1.62 m·sec-1; P < .001) and 2.40 m·sec-1 (IQR, 1.81-2.81 m·sec-1) to 1.15 m·sec-1 (IQR, 0.97-1.60 m·sec-1; P < .001), respectively. Thirty-day major complication rate was 5.1% (hematoma requiring evacuation nLegs = 2, septic bleeding from deep infection nLegs = 1, and iliac occlusion requiring thrombectomy nLegs = 1). In the short term, 91.2% of patients reported symptom reduction with a 93.7% overall satisfaction rate. After a median of 11.1 years (IQR, 7.8-17.6 years), the overall satisfaction was 91.7%; 94.5% of patients reported persistent symptom reduction. Patch dilatation of >20 mm was observed in two patients. Linear mixed model analysis revealed no alarming patch dilatation in the long term. CONCLUSIONS: Endarterectomy with an autologous patch for intermittent claudication owing to iliac artery endofibrosis in endurance athletes shows high rates of patient satisfaction and symptom reduction in both the short and long term. The risk of surgical complications or patch dilatation is mild. A surgical intervention for flow limitation of the iliac artery owing to endofibrosis is safe and successful.

Systematic Review of Innovative Diagnostic Tests for Chronic Exertional Compartment Syndrome.

The diagnosis chronic exertional compartment syndrome is traditionally linked to elevated intracompartmental pressures, although uncertainty regarding this diagnostic instrument is increasing. The aim of current review was to evaluate literature for alternative diagnostic tests. A search in line with PRISMA criteria was conducted. Studies evaluating diagnostic tests for chronic exertional compartment syndrome other than intracompartmental pressure measurements were included. Bias and quality of studies were evaluated using the Oxford Levels of Evidence and the QUADAS-2 instrument. A total of 28 studies met study criteria (MRI n=8, SPECT n=6, NIRS n=4, MRI and NIRS together n=1, miscellaneous modalities n=9). Promising results were reported for MRI (n=4), NIRS (n=4) and SPECT (n=3). These imaging techniques rely on detecting changes of signal intensity in manually selected regions of interest in the muscle compartments of the leg. Yet, diagnostic tools and protocols were diverse. Moreover, five studies explored alternative modalities serving as an adjunct, rather than replacing pressure measurements. Future research is warranted as clinical and methodological heterogeneity were present and high quality validation studies were absent. Further optimization of specific key criteria based on a patient's history, physical examination and symptom provocation may potentially render intracompartmental pressure measurement redundant.

Comparing the Efficacy of Dorsal Root Ganglion Stimulation With Conventional Medical Management in Patients With Chronic Postsurgical Inguinal Pain: Post Hoc Analyzed Results of the SMASHING Study.

OBJECTIVES: Approximately 10% of patients who undergo inguinal hernia repair or Pfannenstiel incision develop chronic (> three months) postsurgical inguinal pain (PSIP). If medication or peripheral nerve blocks fail, a neurectomy is the treatment of choice. However, some patients do not respond to this treatment. In such cases, stimulation of the dorsal root ganglion (DRG) appears to significantly reduce chronic PSIP in selected patients. MATERIALS AND METHODS: In this multicenter, randomized controlled study, DRG stimulation was compared with conventional medical management (CMM) (noninvasive treatments, such as medication, transcutaneous electric neurostimulation, and rehabilitation therapy) in patients with PSIP that was resistant to a neurectomy. Patients were recruited at a tertiary referral center for groin pain (SolviMáx, Eindhoven, The Netherlands) between March 2015 and November 2016. Suitability for implantation was assessed according to the Dutch Neuromodulation Association guidelines. The sponsor discontinued the study early owing to slow enrollment. Of 78 planned patients, 18 were randomized (DRG and CMM groups each had nine patients). Six patients with CMM (67%) crossed over to DRG stimulation at the six-month mark. RESULTS: Fifteen of the 18 patients met the six-month primary end point with a complete data set for a per-protocol analysis. Three patients with DRG stimulation had a negative trial and were lost to follow-up. The average pain reduction was 50% in the DRG stimulation and crossover group (from 6.60 ± 1.24 to 3.28 ± 2.30, p = 0.0029). Conversely, a 13% increase in pain was observed in patients with CMM (from 6.13 ± 2.24 to 6.89 ± 1.24, p = 0.42). Nine patients with DRG stimulation experienced a total of 19 adverse events, such as lead dislocation and pain at the implantation site. CONCLUSIONS: DRG stimulation is a promising effective therapy for pain relief in patients with PSIP resistant to conventional treatment modalities; larger studies should confirm this. The frequency of side effects should be a concern in a new study. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT02349659.

Surgical shortening of lengthened iliac arteries in endurance athletes: Short-term and long-term satisfaction.

OBJECTIVE: Endurance athletes are prone to develop flow limitations in iliac arteries (FLIA). Especially in cyclists and ice speed skaters, excessive hemodynamic loading coupled with hip hyperflexion may cause kinking in lengthened iliac arteries necessitating surgical correction. This study investigated the short-term (≤1.5 years) and long-term (≥5 years) satisfaction of operative shortening of the iliac artery in endurance athletes. METHODS: All patients who were diagnosed and operated for FLIA owing to lengthened and kinked iliac arteries between 1997 and 2015 in one center were analyzed. Short-term follow-up consisted of an incremental maximal cycling test, ankle-brachial index with flexed hips, echo-Doppler examination with peak systolic velocity measurements and contrast-enhanced magnetic resonance angiography before and 6 to 18 months after surgery. Both short- and long-term satisfaction were assessed using questionnaires. RESULTS: A total of 83 patients (90 operated legs; 96.7% males; median age of 34 years at the time of surgery; interquartile range [IQR], 29-47) were analyzed. In the short-term, 87.5% reported symptom reduction with an 86.4% overall satisfaction rate. Symptom-free cycling improved from 272 ± 84 W to 384 ± 101 W (P < .001), whereas the maximal workload increased from 419 ± 72 W to 428 ± 67 W (P = .01). The ankle-brachial index with flexed hips increased from 0.55 (IQR, 0.45-0.65) to 0.62 (IQR, 0.52-0.74; P = .008), and the peak systolic velocity measured with hips flexed decreased from 2.50 m/s (IQR, 1.77-3.13 m/s) to 1.57 m/s (IQR, 1.20-2.04 m/s; P < .001). After a median of 12 years (IQR, 9.0-15.4 years), symptoms were still decreased in 84.1% of patients with an 81.2% overall satisfaction rate (79.5% response rate). Three patients needed a reintervention (recurrent FLIA, n = 2; failure, n = 1). CONCLUSIONS: Operative shortening of a lengthened and kinked iliac artery causing FLIA is successful both in the short- and long-term.

Diagnosing Sport-Related Flow Limitations in the Iliac Arteries Using Near-Infrared Spectroscopy.

Background: A flow limitation in the iliac arteries (FLIA) in endurance athletes is notoriously difficult to diagnose with the currently available diagnostic tools. At present, a commonly used diagnostic measure is a decrease in ankle brachial index with flex hips (ABIFlexed) following a maximal effort exercise test. Near-infrared spectroscopy (NIRS) is a non-invasive technique that measures skeletal muscle oxygenation as reflected by the balance of O2 delivery from microvascular blood flow and O2 uptake by metabolic activity. Therefore, NIRS potentially serves as a novel technique for diagnosing FLIA. The purpose of this study is to compare the diagnostic accuracy of NIRS-derived absolute, amplitude, and kinetic variables in legs during and after a maximal exercise test with ABIFlexed. Methods: ABIFlexed and NIRS were studied in 33 healthy subjects and 201 patients with FLIA diagnosed with echo-Doppler. Results: After maximal exercise, NIRS kinetic variables, such as the half value time and mean response time, resulted in a range of 0.921 to 0.939 AUC for the diagnosis of FLIA when combined with ABIFlexed. Conversely, ABIFlexed measurements alone conferred significantly worse test characteristics (AUC 0.717, p < 0.001). Conclusions: NIRS may serve as a diagnostic adjunct in patients with possible FLIA.

A scoping review on surgical reduction of high flow arteriovenous haemodialysis access.

Volume flow (Qa) > 1.5-2 l /minQa in arteriovenous accesses may be associated with high flow related systemic or locoregional complications. A variety of surgical techniques are advocated for Qa reduction. Aim of this scoping review is to provide an overview of available evidence regarding the efficacy of this broad spectrum of interventions for Qa reduction in patients with a high flow haemodialysis access. PubMed and Embase were searched according to PRISMA-guidelines. Studies on invasive management of HFA were selected. Inclusion required an English description of surgical techniques in human HFAs including pre- and postoperative access flow-values. Sixty-six studies on 940 patients (mean age 56 years (3-90 years), male 62%, diabetes mellitus 26%, brachial artery-based arteriovenous access 65%) fulfilled inclusion criteria. Performed techniques were banding (58%), revision using distal inflow (12%), plication/anastomoplasty (10%), graft interposition (5%), proximal radial artery ligation (3%), aneurysm repair (4%), or miscellaneous other techniques (8%). Definition of HFA, work-up, indication for surgery and intraoperative monitoring were diverse. All techniques reduced Qa on the short term (mean drop 0.9-1.7 l/min). Secondary access patency rates varied between 70% and 93% (mean follow-up 15 (0-189) months). Definitions of success and recurrence varied widely precluding a comparison of efficacy of techniques. Patient specific factors legitimizing invasive treatment for HFA are discussed. Recommendations on reporting standards when dealing with HFA surgery are provided. In conclusion, the present report on the current management of high flow access does not allow for drawing any definite conclusions due to a lack of standardization in definition, indications for surgical intervention and techniques. Randomized trials comparing different Qa reducing techniques in symptomatic patients are warranted, as are trials comparing a wait-and-see approach versus Qa reduction in asymptomatic patients. As an overview of the variety of techniques was lacking, this scoping review might serve as a map for future researchers.

Two-Compartment or 4-Compartment Fasciotomy for Lower Leg Chronic Exertional Compartment Syndrome: A Systematic Review.

Patients with lower leg chronic exertional compartment syndrome are impaired due to exercise-related pain. Fasciotomy is the surgical gold standard. However, it is unknown whether number of simultaneously opened compartments affects outcome. The purpose of this systematic review was to compare patient-reported outcomes of a 2-compartment fasciotomy with a 4-compartment fasciotomy. Controlled clinical trials (randomized/nonrandomized), cohort studies and case series reporting on outcome following either 2-compartment or 4-compartment fasciotomy for lower leg chronic exertional compartment syndrome were searched until May 31, 2021 in PubMed, EMBASE, and Cochrane. Results were qualitatively synthesized. Risk of bias and levels of evidence were determined. Seven studies reporting on altogether 194 athletes and military personnel (mean age 24 y) were included. Quality assessment revealed a high risk of bias in all studies. Both 2-compartment and 4-compartment fasciotomy were associated with a 50% to 100% "return to activity" rate (in studies reporting group results separately: 2-compartment 90%-100%; 4-compartment 50%-100%) and a 41% to 100% "return to previous activity" rate (in studies reporting group results separately: 2-compartment 82-100%; 4-compartment 50%-100%) without significant differences. Mean Marx activity score of 1 study found a small significant standardized mean difference (0.196 [0.524,0.916]) favoring 4-compartment fasciotomy. Rate of satisfaction (2-compartment 74%-89%; 4-compartment 75%-100%) and residual symptoms (2-compartment 0%-36%; 4-compartment 0%-50%) indicated no group differences. In conclusion, a 2-compartment fasciotomy or a 4-compartment fasciotomy for lower leg chronic exertional compartment syndrome appears to be equally successful. However, included studies were hampered by methodological shortcomings (low sample size, selection bias, heterogeneity and no uniform outcome measures).

Short- and long-term results of operative iliac artery release in endurance athletes.

OBJECTIVE: Endurance athletes can develop intermittent claudication due to sports-related flow limitations of the iliac artery (FLIA) caused by arterial kinking. In the present study, we investigated the short- and long-term efficacy of an operative release for iliac artery kinking. METHODS: Between 1996 and 2015, all patients with a diagnosis of FLIA due to iliac artery kinking without substantial arterial stenosis (<15%) or an excessive arterial length (vessel length to straight ratio, <1.25) who had undergone surgery were included. The short-term follow-up protocol consisted of cycling tests, the ankle brachial index with a flexed hip, and Doppler echography examinations to determine the peak systolic velocity before and 6 to 18 months after surgery. Additionally, the short- and long-term efficacy were evaluated using questionnaires. RESULTS: A total of 142 endurance athletes (155 legs; 88.4% male; median age, 26 years; interquartile range [IQR], 22-31 years) were available for analysis. In the short term, the symptoms had decreased in 83.9% of the patients, with an overall 80.3% satisfaction rate. Power during a maximal cycling test had improved from 420 W (IQR, 378-465 W) to 437 W (IQR, 392-485 W; P < .001). The symptom-free workload had increased from 300 W (IQR, 240-340 W) to 400 W (IQR, 330-448 W; P < .001). The postexercise ankle brachial index with a flexed hip had increased from 0.53 (IQR, 0.40-0.61) to 0.57 (IQR, 0.47-0.64; P = .002), and the peak systolic velocity with a flexed hip had decreased from 1.88 m/s (IQR, 1.45-2.50 m/s) to 1.52 m/s (IQR, 1.19-2.07 m/s; P < .001). Postoperative imaging studies revealed some degree kinking in 33.9%, mostly asymptomatic. The long-term results were evaluated after a median of 15.2 years (IQR, 10.9-19.5 years). The athletes had cycled an additional 125.500 km (IQR, 72.00-227.500 km), which was approximately equal to the 131.000 km (IQR, 98.250-220.000 km) cycled before the diagnosis of FLIA. On the long term, 63.9% of the athletes reported persistent reduction of complaints, with an overall 59.1% satisfaction rate. Eight patients had required reintervention, six because of treatment failure and two because of newly developed FLIA. CONCLUSIONS: Operative iliac artery release for sports-related functional kinking in the absence of stenosis or an excessive vessel length was effective for most athletes in the short and long term.

Test-retest reliability of skeletal muscle oxygenation measurement using near-infrared spectroscopy during exercise in patients with sport-related iliac artery flow limitation.

The ankle-brachial index is an accurate tool for detecting claudication in atherosclerotic patients. However, this technique fails to identify subtle flow limitations of the iliac arteries (FLIA) in endurance athletes. Near-infrared spectroscopy (NIRS) is a noninvasive technique that measures skeletal muscle tissue oxygenation status. The aim of the present study is to examine the absolute and relative test-retest reliability of NIRS and evaluate its potential as a diagnostic tool in FLIA. NIRS-derived exercise variables were analyzed during exercise and recovery in FLIA 17 patients and 19 healthy controls. The relative reliability of absolute variables (such as the maximal value) were slight to yet predominantly substantial (intraclass correlation coefficient [ICC], ICC range: 0.06-0.76) with good to excellent absolute reliability (absolute limits of agreement [ALoA], ALoA range: 0.8 ± 10.2 to 0.7 ± 13.1; coefficient of variation [CV], CV range: 5%-11%). Absolute values encompassing signal amplitudes showed moderate to almost perfect relative reliability (ICC range: 0.51-0.89) and poor to good absolute reliability (ALoA range: -1.3 ± 7.0 to -2.5 ± 15.7; CV range: 15%-32%). Kinetic variables showed moderate to almost perfect relative reliability for most recovery kinetics variables (ICC range: 0.54-0.86) with fair to good absolute reliability (ALoA range: 0.4 ± 12.2 to 3.9 ± 37.9; CV range: 18%-27%). Particularly, kinetic variables showed significant differences between patients and healthy subjects. NIRS is found to be a reliable method for examining muscle tissue oxygenation variables. Given the significant differences in especially recovery kinetics between normal subjects and patients, NIRS may contribute to diagnosing FLIA in endurance athletes.

Access flow volume (Qa) and survival in a haemodialysis population: an analysis of 5208 Qa measurements over a 9-year period.

BACKGROUND: The aim of this study was to determine associations between characteristics of arteriovenous access (AVA) flow volume (Qa; mL/min) and 4-year freedom from cardiovascular mortality (CVM) in haemodialysis (HD) patients. METHODS: HD patients who received a primary AVA between January 2010 and December 2017 in one centre were analysed. Initial Qa was defined as the first Qa value obtained in a well-functioning AVA by a two-needle dilution technique. Actual Qa was defined as access flow at a random point in time. Changes in actual Qa were expressed per 3-month period. CVM was assessed according to the European Renal Association-European Dialysis and Transplant Association classification. The optimal cut-off point for initial Qa was identified by a receiver operating characteristics curve. A joint modelling statistical technique determined longitudinal associations between Qa characteristics and 4-year CVM. RESULTS: A total of 5208 Qa measurements (165 patients; 103 male, age 70 ± 12 years, autologous AVA n = 146, graft n = 19) were analysed. During follow-up (December 2010-January 2018, median 36 months), 79 patients (48%) died. An initial Qa <900 mL/min was associated with an increased 4-y CVM risk {hazard ratio [HR] 4.05 [95% confidence interval (CI) 1.94-8.43], P < 0.001}. After 4 years, freedom from CVM was 34% lower in patients with a Qa <900 mL/min (53 ± 7%) versus a Qa ≥900 mL/min (87 ± 4%; P < 0.001). An association between increases in actual Qa per 3-month period and mortality was found [HR 4.48/100 mL/min (95% CI 1.44-13.97), P = 0.010], indicating that patients demonstrating increasing Qa were more likely to die. In contrast, actual Qa per se was not related to survival. CONCLUSIONS: Studying novel AVA Qa characteristics may contribute to understanding excess CVM in HD patients.