Mitral Valve Replacement Using Subvalvular Apparatus: A Systematic Review and Meta-Analysis.

BACKGROUND: To assess clinical outcomes among participants undergoing mitral valve replacement with preservation of subvalvular apparatus. METHODS: Electronic databases, including PubMed, Embase, Science Direct, World of Science, Scopus, Biosis, SciElo and Cochrane library, were probed using an extensive search strategy. Studies that reported at least one clinical outcome, such as morbidity, mortality, early 30-day mortality, myocardial failure, survival, late cerebrovascular events, length of stay, or major operative complications (stroke, prolonged ventilation, and reoperation for bleeding, renal failure, and sternal infection) were considered for inclusion. Data was extracted and pooled into a meta-analysis in RevMan (version 5.3) using a random-effects model. RESULTS: A total of 21 studies with 5,106 participants (age range: 27.3-69.2 years) were included in this meta-analysis. Preservation of the subvalvular apparatus during MVR significantly reduces the risk of long-term mortality (OR: 0.46; 95% CI: 0.33-0.64), but not early mortality (OR: 0.76; 95% CI: 0.12-4.93). No significant difference ejection fraction was observed (SMD: 0.10; 95% CI: -0.44-0.64). Similarly, there was no significant difference in the risk of stroke, renal failure, and pneumonia between C-MVR and in the control group. CONCLUSION: MVR with the preservation of subvalvular apparatus improves clinical outcomes, such as long-term mortality, hospital length of stay, pneumonia, and bleeding. There is no significant difference in the risk of stroke, renal failure, or ICU length of stay. However, there is very limited data available with respect to bleeding, sepsis, and nosocomial infections.

Laboratory abnormalities in children with mild and severe coronavirus disease 2019 (COVID-19): A pooled analysis and review.

Limited data exists to-date on the laboratory findings in children with COVID-19, warranting the conduction of this study, in which we pool the currently available literature data on the laboratory findings seen in children with mild and severe COVID-19. Following an extensive literature search, we identified 24 eligible studies, including a total of 624 pediatric cases with laboratory-confirmed COVID-19, which report data on 27 different biomarkers. We then performed a meta-analysis to calculate the pooled prevalence estimates (PPE) for these laboratory abnormalities in mild COVID-19. As data was too limited for children with severe COVID-19 to allow pooling, results were presented descriptively in a summary of findings table. Our data show an inconsistent pattern of change in the leukocyte index of mild and severe cases of COVID-19 in children. Specifically, changes in leukocyte counts were only observed in 32% of the mild pediatric cases (PPE: 13% increase, 19% decrease). In mild disease, creatine kinase-MB (CK-MB) was frequently elevated, with a PPE of 33%. In severe disease, c-reactive protein (CRP), procalcitonin (PCT), and lactate dehydrogenase (LDH) were frequently elevated. Based on data obtained from early COVID-19 studies, leukocyte indices in children appear inconsistent, differing from those reported in adults that highlight specific leukocyte trends. This brings into question the utility and reliability of such parameters in monitoring disease severity in the pediatric population. Instead, we suggest physicians to serially monitor CRP, PCT, and LDH to track the course of illness in hospitalized children. Finally, elevated CK-MB in mild pediatric COVID-19 cases is indicative of possible cardiac injury. This highlights the importance of monitoring cardiac biomarkers in hospitalized patients and the need for further investigation of markers such as cardiac troponin in future studies.

Serum albumin in patients undergoing transcatheter aortic valve replacement: A meta-analysis.

Transcatheter aortic valve replacement is becoming a more common therapeutic option for the treatment of aortic stenosis in patients at high risk for invasive surgery, but detecting which patients will benefit clinically can be challenging. Hypoalbuminemia is a useful prognostic marker for chronic inflammation in this population. We carried out a systematic review and meta-analysis of studies evaluating the prognostic value of serum albumin level in patients undergoing transcatheter aortic valve replacement. A literature search of PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Wanfang, and CNKI databases was conducted. Articles published between January 2000 and December 2017 reporting on the prognostic value of low levels of serum albumin in patients undergoing transcatheter aortic valve replacement were analyzed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. 11 studies including 6456 patients met inclusion criteria for meta-analysis. A lower serum albumin level was associated with a lower survival rate at follow-up in patients who underwent transcatheter aortic valve replacement. A sub-group analysis of eight studies reporting adjusted hazard ratios indicated that low serum albumin was independently correlated with increased post-operative mortality. The hazard ratio of mortality risk associated with each 1 g/dL increment in serum albumin level was 0.46, suggesting a potential dose-response relationship between increased serum albumin level and increased survival rate in patients undergoing transcatheter aortic valve replacement. This meta-analysis provides strong evidence for the utility of serum albumin as a prognostic marker in aortic stenosis patients undergoing transcatheter aortic valve replacement, with low serum albumin levels (2.5-3.5 g/dL) suggesting poor prognosis.

Prognostic Factors for Long-Term Survival after Surgical Resection of Primary Cardiac Sarcoma.

BACKGROUND: Primary cardiac sarcoma (CS) is an extremely rare disease. This study aims to identify possible prognostic factors for long-term survival. METHODS: A total of 17 consecutive patients who were treated for primary CS between 2003 und 2018 at two cardiac centers were investigated. Clinical data and histological characteristics of the tumors were analyzed. Long-term follow-up of all patients were performed. RESULTS: The median age was 54 years (range: 23-74). The tumors originated from the left side of the heart in nine patients. Histologically, there were four angiosarcomas, three intimal sarcomas, and three synovial sarcomas. One- and 7-year survivals were 81.9 and 18.2%, respectively. Low expression levels of Ki-67 tended to be associated with increased survival (log-rank p = 0.06). Adjuvant chemotherapy but not radiotherapy regardless of existing metastases was associated with significantly increased survival (log-rank p = 0.001). CONCLUSION: Angiosarcoma was the most common type of CS. The survival of CS patients is poor but prognostic factors, such as Ki-67, may help estimate the course of the disease. Survival could be improved significantly with chemotherapy.

Prognostic Role of Admission C-Reactive Protein Level as a Predictor of In-Hospital Mortality in Type-A Acute Aortic Dissection: A Meta-Analysis.

BACKGROUND: Acute aortic dissection (AD) is a lethal vascular disease, accounting for over 90% cases of acute aortic syndrome. Despite advances in understanding associated risk factors, the long-term prognosis for AD patients is still poor. Several prognostic biomarkers have been used for AD as per the IRAD, such as older age (>70 years), onset of chest pain and hypotension, but they are not effective in all patients. Instead, C-reactive protein (CRP) is a consistent inflammatory marker. CRP levels are abnormally increased in AD. However, the prognostic value of serum CRP level in AD remains unclear. OBJECTIVE: To perform a systematic review and meta-analysis (registration no CRD42017056205) to evaluate whether CRP is a biomarker associated with in-hospital mortality in type-A AD. METHODS: PubMed, Web of Science, CNKI, SciELO, and EMBASE were searched for papers published from January 2000 to October 2017 for studies on the prognostic role of CRP at admission in type-A AD patients. Outcome data were extracted and pooled hazard ratios (HRs) were calculated. RESULTS: 18 (N = 2875 patients) studies met the inclusion criteria. Elevated CRP level was associated with a significantly increased risk of in-hospital mortality in patients with type-A AD (HR = 1.15, 95% CI: 1.06-1.25, p = 0.001). The pooled sensitivity of CRP in type-A AD patients was 77% (95% CI 69%-84%, p < 0.001), and the specificity was 72% (95% CI 66%-78%, p < 0.001). CONCLUSION: Elevated CRP level is significantly associated with increased risks of in-hospital mortality in patients with type-A AD. CRP is a convenient prognostic factor in type-A AD patients.

Artery of Adamkiewicz: a meta-analysis of anatomical characteristics.

PURPOSE: The artery of Adamkiewicz (AKA) provides the major blood supply to the anterior thoracolumbar spinal cord and iatrogenic injury or inadequate reconstruction of this vessel during vascular and endovascular surgery can result in postoperative neurological deficit due to spinal cord ischemia. The aim of this study was to provide comprehensive data on the prevalence and anatomical characteristics of the AKA. METHODS: An extensive search was conducted through the major electronic databases to identify eligible articles. Data extracted included study type, prevalence of the AKA, gender, number of AKA per patient, laterality, origin based on vertebral level, side of origin, morphometric data, and ethnicity subgroups. RESULTS: A total of 60 studies (n = 5437 subjects) were included in the meta-analysis. Our main findings revealed that the AKA was present in 84.6% of the population, and patients most frequently had a single AKA (87.4%) on the left side (76.6%) originating between T8 and L1 (89%). CONCLUSION: As an AKA is present in the majority of the population, caution should be taken during vascular and endovascular surgical procedures to avoid injury or ensure proper reconstruction. All surgeons operating in the thoracolumbar spinal cord should have a thorough understanding of the anatomical characteristics and surgical implications of an AKA.

Incidence, Risk Factors, and Comorbidities of Vocal Cord Paralysis After Surgical Closure of a Patent Ductus Arteriosus: A Meta-analysis.

Surgical closure of a patent ductus arteriosus (PDA) is considered standard treatment for symptomatic neonates refractory to medical therapy. Sometimes, iatrogenic injury to the left recurrent laryngeal nerve during the procedure can result in vocal cord paralysis (VCP). This study aimed to estimate the incidence of VCP in patients after surgical PDA closure and to identify any associated risk factors and morbidities associated with VCP in the preterm infant population. A thorough search of the major electronic databases was conducted to identify studies eligible for inclusion into this meta-analysis. Studies reporting data on the incidence of VCP (primary outcomes) or risk factors and morbidities associated with VCP in premature infant population (secondary outcomes) were included. A total of 33 studies (n = 4887 patients) were included into the analysis. Overall pooled incidence estimate of VCP was 7.9% (95%CI 5.3-10.9). The incidence of VCP after PDA closure was significantly much higher in premature infants (11.2% [95%CI 7.0-16.3]) than in non-premature patients (3.0% [95%CI 1.5-4.9]). The data showed that VCP was most common after surgical ligation and in studies conducting universal laryngoscopy scoping. The risk factors for postoperative VCP in preterm infants included birth weight and gestational age. In addition, VCP was significantly associated with the occurrence of bronchopulmonary dysplasia, gastrostomy tube insertion, and increased duration of mechanical ventilation. Vocal cord paralysis remains a frequent complication of surgical closure of a PDA, especially in premature neonates, and is associated with significant post-procedural complications.

Model for end-stage liver disease predicts mortality after pericardiectomy for constrictive pericarditis.

OBJECTIVES: Prognosis after pericardiectomy for constrictive pericarditis (CP) is affected by the aetiology of the constriction as well as by concomitant cardiac and non-cardiac disease, including liver dysfunction. However, few data exist on the risk stratification that accounts for liver function in patients with CP. We evaluated the effectiveness of the model for end-stage liver disease (MELD) score, an established measure of liver dysfunction, in predicting long-term survival and identifying other risk factors for death. METHODS: A total of 79 patients who underwent pericardiectomy for CP at a single centre between 2009 and 2016 were analysed. The prognostic utility of the MELD score was evaluated in our cohort. Logistic regression and Cox proportional hazard regression analyses were performed to assess the association of various clinical variables with 1-year and overall mortality rates. RESULTS: With multivariable analysis, only the MELD score was an independent predictor of 1-year mortality (P < 0.001); apart from the MELD (P = 0.003) score, post-surgical CP (P = 0.016), total bilirubin level (P = 0.042) and the European System for Cardiac Operative Risk Evaluation score II (P = 0.002) were independent predictors of overall mortality after pericardiectomy. Overall survival decreased as the MELD score increased. Scores ≤ 7.5, 7.51-15.50 and >15.5 were associated with overall survival rates of 92.9%, 69.8% and 8.3%, respectively. CONCLUSIONS: In addition to the underlying aetiology, we demonstrated that assessment of liver dysfunction using the MELD score provides additional information about risk because it is associated with postoperative death in patients undergoing pericardiectomy for CP.

Residual pulmonary hypertension after pulmonary endarterectomy: A meta-analysis.

OBJECTIVE: Chronic thromboembolic pulmonary hypertension is surgically treated through pulmonary endarterectomy. Although pulmonary endarterectomy is the treatment of choice for chronic thromboembolic pulmonary hypertension in terms of both functional outcomes and survival, many patients experience persistent pulmonary hypertension after pulmonary endarterectomy. The study objective was to calculate the pooled estimates of outcomes after pulmonary endarterectomy, including persistent pulmonary hypertension. METHODS: Meta-analyses were conducted on published studies reporting residual/persistent/recurrent pulmonary hypertension in 4868 patients with chronic thromboembolic pulmonary hypertension after pulmonary endarterectomy. The rate of persistent pulmonary hypertension and change in mean pulmonary artery pressure, pulmonary vascular resistance, and 6-minute walk distance after pulmonary endarterectomy were outcomes of interest. RESULTS: Twenty-five percent of patients with chronic thromboembolic pulmonary hypertension were diagnosed with persistent pulmonary hypertension after pulmonary endarterectomy. Pulmonary endarterectomy reduced mean pulmonary artery pressure and pulmonary vascular resistance by approximately 21 mm Hg (standardized mean difference, 1.75; 95% confidence interval, -1.62 to 1.88; P < .00001) and 561 dyn.s/cm5 (standardized mean difference, 1.64; 95% confidence interval, -1.58 to 1.70; P < .00001), respectively. Conversely, 6-minute walk distance increased by 96 m (standardized mean difference, -0.83; 95% confidence interval, -0.91 to -0.76; P < .00001) after pulmonary endarterectomy. CONCLUSIONS: Pulmonary endarterectomy is the gold standard treatment for chronic thromboembolic pulmonary hypertension and provides immediate correction of hemodynamic parameters in most patients. However, in up to one quarter of operable cases, pulmonary hypertension persists after surgery. In those patients with persistent pulmonary hypertension, continued medical management with newer agents may be required to improve pulmonary hemodynamics and, therefore, patient outcomes.

Novel approaches to study coronary vasculature development in mice.

BACKGROUND: Coronary artery development is an intensely studied field. Mice are a popular genetic model for developmental studies, but there is no widely accepted protocol for high-throughput, high-resolution imaging of their developmental and adult coronary artery anatomy. RESULTS: Using tissue-clearing protocols and confocal microscopy, we have analyzed embryonic and juvenile mouse hearts in Cx40:GFP knock-in models with a special focus on septal artery development. We found that the septal artery, which supplies the interventricular septum, was initially formed as an arterial plexus that connected to both the left and right coronary arteries. During development, the plexus was remodeled into a single tube, which then remained connected only to the right coronary artery. Since optical imaging became limited at postnatal stages, it was supplemented with injection techniques using India ink and Microfil; the latter was subsequently analyzed with micro-CT to visualize the anatomy of coronary vessels in 3D. CONCLUSIONS: The techniques described here enable us to study the finer details of coronary artery development in mice and can, therefore, be implemented to study the pathogenesis of coronary malformations in various mouse models. Developmental Dynamics 247:1018-1027, 2018. © 2018 Wiley Periodicals, Inc.

A systematic review and meta-analysis of variations in branching patterns of the adult aortic arch.

OBJECTIVE: The aortic arch (AA) is the main conduit of the left side of the heart, providing a blood supply to the head, neck, and upper limbs. As it travels through the thorax, the pattern in which it gives off the branches to supply these structures can vary. Variations of these branching patterns have been studied; however, a study providing a comprehensive incidence of these variations has not yet been conducted. The objective of this study was to perform a meta-analysis of all the studies that report prevalence data on AA variants and to provide incidence data on the most common variants. METHODS: A systematic search of online databases including PubMed, Embase, Scopus, ScienceDirect, Web of Science, SciELO, BIOSIS, and CNKI was performed for literature describing incidence of AA variations in adults. Studies including prevalence data on adult patients or cadavers were collected and their data analyzed. RESULTS: A total of 51 articles were included (N = 23,882 arches). Seven of the most common variants were analyzed. The most common variants found included the classic branching pattern, defined as a brachiocephalic trunk, a left common carotid, and a left subclavian artery (80.9%); the bovine arch variant (13.6%); and the left vertebral artery variant (2.8%). Compared by geographic data, bovine arch variants were noted to have a prevalence as high as 26.8% in African populations. CONCLUSIONS: Although patients who have an AA variant are often asymptomatic, they compose a significant portion of the population of patients and pose a greater risk of hemorrhage and ischemia during surgery in the thorax. Because of the possibility of encountering such variants, it is prudent for surgeons to consider potential variations in planning procedures, especially of an endovascular nature, in the thorax.

Applicability of handmade expanded polytetrafluoroethylene trileaflet-valved conduits for pulmonary valve reconstruction: An ex vivo and in vivo study.

OBJECTIVE: The handmade expanded polytetrafluoroethylene (ePTFE) trileaflet-valved conduit could potentially be used as a substitute pulmonary valve replacement material, especially in children. The current study investigated (1) the function of the ePTFE trileaflet-valved conduits in an ex vivo experimental system and (2) the short-term performance of the conduit in a porcine model to verify its clinical applicability. METHODS: The competency of the ePTFE trileaflet-valved conduits was estimated through ex vivo (using a pulmonary mock circulation loop) and in vivo (in a porcine model with a damaged pulmonary valve) experiments. Explants were examined by gross morphology and histopathologic examination. RESULTS: In the ex vivo experiment, the ePTFE trileaflet-valved conduits were determined to effectively increase mean pulmonary pressure from 10.2 to 14.4 mm Hg compared with defective silicon-valved conduits. In addition, the regurgitation fraction value of ePTFE trileaflet-valved conduits was 15.9% to 18.1%, which was significantly better than the defective valve conduits (regurgitation fraction = 73.5%-85.7%). In the in vivo experiment, the valved conduits were confirmed to be with good valve position maintenance, and the valve and leaflets showed no signs of thickening or peeling after a short-term implantation period. There were also no significant signs of inflammation reaction on histopathologic examination. CONCLUSIONS: The ePTFE trileaflet-valved conduits for pulmonary valve reconstruction showed acceptable performance and outcomes in the ex vivo and in vivo experiments. The ePTFE trileaflet-valved conduit may be clinically useful, although additional studies in animals should be conducted to determine its long-term outcomes.

Origin and prevalence of the accessory phrenic nerve: A meta-analysis and clinical appraisal.

The accessory phrenic nerve (APN) is a common anatomical variant with differing reports of prevalence in the literature. It can be injured during operative procedures to the neck and thorax or by regional anesthetic techniques in its vicinity. Our aim was to provide a comprehensive evidence-based assessment of the prevalence and origins of the APN. The databases PubMed, China National Knowledge Infrastructure, ScienceDirect, EMBASE, BIOSIS, SciELO, and Web of Science were searched comprehensively, followed by assessment of eligibility and extraction of data concerning the APN. The data were pooled into a meta-analysis. A total of 17 studies were included in the meta-analysis. Fourteen studies (n = 1,941 hemi-necks) reported data on APN prevalence resulting in an overall pooled prevalence estimate of 36.5%. Nine studies (n = 941 APNs) reported data on the origin of the APN. Most commonly the APN originated from the ansa cervicalis (16.5%) followed by the nerve to the subclavius (15.8%). Subgroup analysis on the basis of laterality and geographic region revealed no statistically significant findings. The APN is a highly variable anatomical structure present in over one third of the population, most often originating from the ansa cervicalis or the nerve to the subclavius. Clinicians need to be aware of the varying constellation of symptoms that can arise from APN injury. Ultimately, knowledge of APN variation could provide for better outcomes and reduction of iatrogenic injuries, particularly in high-risk patients prone to long-term complications from diaphragmatic dysfunction. Clin. Anat. 30:1077-1082, 2017. © 2017 Wiley Periodicals, Inc.

Prevalence of foramen arcuale and its clinical significance: a meta-analysis of 55,985 subjects.

OBJECTIVE The foramen arcuale (FA) is a bony bridge located over the vertebral artery on the posterior arch of the atlas. The presence of an FA can pose a risk during neurosurgery by providing a false impression of a broader posterior arch. The aim of this study was to provide the most comprehensive investigation on the prevalence of the FA and its clinically important anatomical features. METHODS Major electronic databases were searched to identify all studies that reported relevant data on the FA and the data were pooled into a meta-analysis. RESULTS A total of 127 studies (involving 55,985 subjects) were included. The overall pooled prevalence of a complete FA was 9.1% (95% CI 8.2%-10.1%) versus an incomplete FA, which was 13.6% (95% CI 11.2%-16.2%). The complete FA was found to be most prevalent in North Americans (11.3%) and Europeans (11.2%), and least prevalent among Asians (7.5%). In males (10.4%) the complete FA was more common than in females (7.3%) but an incomplete FA was more commonly seen in females (18.5%) than in males (16.7%). In the presence of a complete FA, a contralateral FA (complete or incomplete) was found in 53.1% of cases. CONCLUSIONS Surgeons should consider the risk for the presence of an FA prior to procedures on the atlas in each patient according to sex and ethnic group. We suggest preoperative screening with computerized tomography as the gold standard for detecting the presence of an FA.

Origin, Branching, and Communications of the Intercostobrachial Nerve: a Meta-Analysis with Implications for Mastectomy and Axillary Lymph Node Dissection in Breast Cancer.

The intercostobrachial nerve (ICBN), which usually originates from the lateral cutaneous branch of the second intercostal nerve, innervates areas of the axilla, lateral chest, and medial arm. It is at risk for injury during operative procedures that are often used in the management of breast cancer and such injury has been associated with postoperative sensory loss and neuropathic pain, decreasing the quality of life. PubMed, Excerpta Medica Database (EMBASE), ScienceDirect, Google Scholar, China National Knowledge Infrastructure (CNKI), Scientific Electronic Library Online (SciELO), Biosciences Information Service (BIOSIS), and Web of Science were searched comprehensively. Data concerning the prevalence, branching, origin and communications of the ICBN were extracted and pooled into a meta-analysis. A total of 16 studies (1,567 axillas) reported data indicating that the ICBN was present in 98.4% of person. It most often (90.6%) originated from fibers at the T2 spinal level and commonly coursed in two branching patterns: as a single trunk in 47.0% of cases and as a bifurcating pattern in 42.2%. In the latter cases, the bifurcation was usually unequal (63.4%). Additionally, the ICBN presented with anastomosing communication to the brachial plexus in 41.3% of cases. The ICBN is a prevalent and variable structure at significant risk for injury during operative procedures of the axilla. In view of the postoperative pain and paresthesia experienced by patients following injury, surgeons need to exercise caution and aim to preserve the ICBN when possible. Ultimately, careful dissection and knowledge of ICBN anatomy could allow postoperative complications to be reduced and patient's quality of life increased.

The evidence-based surgical anatomy of the popliteal artery and the variations in its branching patterns.

OBJECTIVE: The goal of our study was to analyze the prevalence of branching pattern variations in the popliteal artery (PA) along with morphometrics of the PA to better address its importance in disease and vascular surgical procedures. METHODS: An extensive search for the PA and its anatomic variations was done in the major online medical databases. The anatomic data found were extracted and pooled for a meta-analysis. RESULTS: A total of 33 studies (N = 12,757 lower limbs) were included in the analysis. The most common variant was a division of the PA below the knee into the anterior tibial artery and a common trunk for the posterior tibial and peroneal arteries, with a prevalence of 92.6% (95% confidence interval [CI], 90.2-93.8). The second most common variation was a trifurcation pattern of all three branches dividing within 0.5 cm of each other, with a prevalence of 2.4% (95% CI, 1.4-3.5). Of the three studies that reported the diameter of the PA at the level of the subcondylar plane, a mean diameter of 8 mm (95% CI, 7.29-8.70) was found. CONCLUSIONS: The PA most commonly divides below the knee into the anterior tibial artery and the common trunk of the posterior tibial artery and the peroneal artery. Knowledge of the prevalence of possible variations in this anatomy as well as morphometric data is crucial in the planning and execution of any surgical intervention in the area of the knee.

Variations in the origin of the deep femoral artery: A meta-analysis.

The deep femoral artery (DFA) is the largest branch of the femoral artery (FA) and is responsible for vascularization of the thigh muscles. Knowledge of the anatomical variations in its origin point is important for surgeons and interventional radiologists. The aim of our study was to provide a comprehensive evidence-based assessment of its anatomical properties. An extensive search through the major electronic databases was conducted to find all articles reporting data on the anatomical characteristics of the DFA. No date limits or language restrictions were imposed. A total of 25 articles (n = 2,502 lower limbs) were included in the meta-analysis. Six different patterns of origin of the DFA from the FA were identified, the most common type being a posterior origin (38.8%, 95% CI 22.8-49.5%). The DFA most commonly branched off in the proximal third of the thigh, with a prevalence of 47.6% (95% CI 35.8-59.2%). The pooled mean distance of the DFA from its point of origin to the mid-inguinal point was 41.15 mm (95% CI 32.39-53.73). The point and level of origin of the DFA from the FA varies widely in the general population. Owing to this variability, accurate anatomical knowledge regarding the DFA is crucial for clinicians if iatrogenic injuries are to be avoided during procedures in the femoral region. Clin. Anat. 30:106-113, 2017. © 2016 Wiley Periodicals, Inc.