Duplication of the superficial femoral vein: recognition with duplex ultrasonography

Prevalence of femoral vein duplication: systematic review and metaanalysis

Background: Duplication of the femoral vein is an important anatomical variation of the venous anatomy which has been shown to have an impact on the diagnosis of deep venous thrombosis by compression ultrasonography. The presence of duplication may result in false negative findings while evaluating for deep venous thrombosis, with serious consequences such as pulmonary embolism and death. This metaanalysis aims to determine the pooled prevalence of duplicated femoral veins. Methods: A systematic search was conducted through the major databases PubMed, Hinari, Embase and Medline to identify studies eligible for inclusion. Appropriate data were extracted and pooled into a random-effects metaanalysis using MetaXL software. The primary and secondary outcomes of the study included the pooled prevalence of duplicated femoral veins and the prevalence of bilaterally duplicated femoral veins, respectively. Results: A total of 11 studies (n = 3,682 limbs) were included. The overall pooled prevalence of duplicated femoral veins was 19.7% (95% CI 11–30). There was a significant difference in prevalence between cadaveric studies (2%, 95% CI 1–4) and imaging studies (25%, 95% CI 17–34). Conclusion: Duplication of the femoral vein is a common variation in the lower limbs. Routine watch-out should be practiced especially when performing lower limb Doppler studies in cases of deep venous thrombosis in order to avoid misdiagnosis and improve diagnostic accuracy.

Recommendations on the Use of Ultrasound Guidance for Central and Peripheral Vascular Access in Adults: A Position Statement of the Society of Hospital Medicine

PREPROCEDURE

1)We recommend that providers should be familiar with the operation of their specific ultrasound machine prior to initiation of a vascular access procedure. 2)We recommend that providers should use a high-frequency linear transducer with a sterile sheath and sterile gel to perform vascular access procedures. 3)We recommend that providers should use two-dimensional ultrasound to evaluate for anatomical variations and absence of vascular thrombosis during preprocedural site selection. 4)We recommend that providers should evaluate the target blood vessel size and depth during preprocedural ultrasound evaluation.

TECHNIQUES

General Techniques 5) We recommend that providers should avoid using static ultrasound alone to mark the needle insertion site for vascular access procedures. 6)We recommend that providers should use real-time (dynamic), two-dimensional ultrasound guidance with a high-frequency linear transducer for central venous catheter (CVC) insertion, regardless of the provider's level of experience. 7)We suggest using either a transverse (short-axis) or longitudinal (long-axis) approach when performing real-time ultrasound-guided vascular access procedures. 8)We recommend that providers should visualize the needle tip and guidewire in the target vein prior to vessel dilatation. 9)To increase the success rate of ultrasound-guided vascular access procedures, we recommend that providers should utilize echogenic needles, plastic needle guides, and/or ultrasound beam steering when available. Central Venous Access Techniques 10) We recommend that providers should use a standardized procedure checklist that includes the use of real-time ultrasound guidance to reduce the risk of central line-associated bloodstream infection (CLABSI) from CVC insertion. 11)We recommend that providers should use real-time ultrasound guidance, combined with aseptic technique and maximal sterile barrier precautions, to reduce the incidence of infectious complications from CVC insertion. 12)We recommend that providers should use real-time ultrasound guidance for internal jugular vein catheterization, which reduces the risk of mechanical and infectious complications, the number of needle passes, and time to cannulation and increases overall procedure success rates. 13)We recommend that providers who routinely insert subclavian vein CVCs should use real-time ultrasound guidance, which has been shown to reduce the risk of mechanical complications and number of needle passes and increase overall procedure success rates compared with landmark-based techniques. 14)We recommend that providers should use real-time ultrasound guidance for femoral venous access, which has been shown to reduce the risk of arterial punctures and total procedure time and increase overall procedure success rates. Peripheral Venous Access Techniques 15) We recommend that providers should use real-time ultrasound guidance for the insertion of peripherally inserted central catheters (PICCs), which is associated with higher procedure success rates and may be more cost effective compared with landmark-based techniques. 16)We recommend that providers should use real-time ultrasound guidance for the placement of peripheral intravenous lines (PIV) in patients with difficult peripheral venous access to reduce the total procedure time, needle insertion attempts, and needle redirections. Ultrasound-guided PIV insertion is also an effective alternative to CVC insertion in patients with difficult venous access. 17)We suggest using real-time ultrasound guidance to reduce the risk of vascular, infectious, and neurological complications during PIV insertion, particularly in patients with difficult venous access. Arterial Access Techniques 18)We recommend that providers should use real-time ultrasound guidance for arterial access, which has been shown to increase first-pass success rates, reduce the time to cannulation, and reduce the risk of hematoma development compared with landmark-based techniques. 19)We recommend that providers should use real-time ultrasound guidance for femoral arterial access, which has been shown to increase first-pass success rates and reduce the risk of vascular complications. 20)We recommend that providers should use real-time ultrasound guidance for radial arterial access, which has been shown to increase first-pass success rates, reduce the time to successful cannulation, and reduce the risk of complications compared with landmark-based techniques.

POSTPROCEDURE

21) We recommend that post-procedure pneumothorax should be ruled out by the detection of bilateral lung sliding using a high-frequency linear transducer before and after insertion of internal jugular and subclavian vein CVCs. 22)We recommend that providers should use ultrasound with rapid infusion of agitated saline to visualize a right atrial swirl sign (RASS) for detecting catheter tip misplacement during CVC insertion. The use of RASS to detect the catheter tip may be considered an advanced skill that requires specific training and expertise.

TRAINING

23) To reduce the risk of mechanical and infectious complications, we recommend that novice providers should complete a systematic training program that includes a combination of simulation-based practice, supervised insertion on patients, and evaluation by an expert operator before attempting ultrasound-guided CVC insertion independently on patients. 24)We recommend that cognitive training in ultrasound-guided CVC insertion should include basic anatomy, ultrasound physics, ultrasound machine knobology, fundamentals of image acquisition and interpretation, detection and management of procedural complications, infection prevention strategies, and pathways to attain competency. 25)We recommend that trainees should demonstrate minimal competence before placing ultrasound-guided CVCs independently. A minimum number of CVC insertions may inform this determination, but a proctored assessment of competence is most important. 26)We recommend that didactic and hands-on training for trainees should coincide with anticipated times of increased performance of vascular access procedures. Refresher training sessions should be offered periodically. 27)We recommend that competency assessments should include formal evaluation of knowledge and technical skills using standardized assessment tools. 28)We recommend that competency assessments should evaluate for proficiency in the following knowledge and skills of CVC insertion: (a) Knowledge of the target vein anatomy, proper vessel identification, and recognition of anatomical variants; (b) Demonstration of CVC insertion with no technical errors based on a procedural checklist; (c) Recognition and management of acute complications, including emergency management of life-threatening complications; (d) Real-time needle tip tracking with ultrasound and cannulation on the first attempt in at least five consecutive simulation. 29)We recommend a periodic proficiency assessment of all operators should be conducted to ensure maintenance of competency.

Operative technique and morbidity of superficial femoral vein harvest

Background

The use of autologous superficial femoral veins (SFV) as an arterial or venous substitute represents a valuable technique in modern vascular surgery with versatile indications. The SFV autografts exhibit excellent control of infection and durable long-term results in terms of graft patency in prosthetic or arterial infections. In cases of elective use of the SFV, duplex ultrasound evaluation of the deep leg vein system should be implemented to confirm the patency of the profunda femoris vein.

Material and methods

The SFV can be harvested distal to the adductor hiatus with a proximal portion of the popliteal vein but should not exceed the level of the knee joint. Formation of a stump of the proximal SFV must be avoided. Simultaneous harvesting of the ipsilateral greater saphenous vein should be avoided to reduce the risk of significant chronic edema.

Results

Early postoperative swelling of the donor leg can be expected but resolves spontaneously in most cases. Chronic mild edema of the leg with a possible indication for compression therapy may occur in up to 20 % of cases but severe complications are very rare if the anatomical borders for vein harvesting are respected. Temporary therapeutic anticoagulation after vein harvest is subject to individual decision making.

Conclusion

Duplex ultrasound is a reliable tool to assess the residual deep and superficial venous system in the long term. Excellent graft function and the tolerable adverse effects of vein harvest on the donor leg justify the use of the SFV in arterial and venous vascular surgery if indicated.

The deep venous system of the lower extremity: new nomenclature

The correct and precise nomenclature of the veins of the lower extremity is a necessary tool for communication. Three important changes have been done over the last 13 years. Terminologia Anatomica, the latest version of the Latin anatomical nomenclature, was published in 1998, extended in the area of the lower extremity veins with two consensus documents, in 2001, during the 14th World Congress of the International Union of Phlebology and in 2004 during the 21st World Congress of the International Union of Angiology. This article is a free continuation of two previous articles, reviewing the detailed anatomy and correct nomenclature of the superficial veins of the lower extremities and veins of pelvis. Now, it is concentrated on the deep venous system, in which 15 new terms have been added in both Latin and English languages.

Three-dimensional evaluation of the anatomic variations of the femoral vein and popliteal vein in relation to the accompanying artery by using CT venography

OBJECTIVE

We wanted to describe the three-dimensional (3D) anatomic variations of the femoral vein (FV) and popliteal vein (PV) in relation to the accompanying artery using CT venography.

MATERIALS AND METHODS

We performed a retrospective review of 445 bilateral (890 limbs) lower limb CT venograms. After the 3D relationship between the FV and PV and accompanying artery was analyzed, the presence or absence of variation was determined and the observed variations were classified. In each patient, the extent and location of the variations and the location of the adductor hiatus were recorded to investigate the regional frequency of the variations.

RESULTS

THERE WERE FOUR DISTINCT CATEGORIES OF VARIATIONS: agenesis (3 limbs, 0.3%), multiplication (isolated in the FV: 190 limbs, 21%; isolated in the PV: 14 limbs, 2%; and in both the FV and PV: 51 limbs, 6%), anatomical course variation (75 limbs, 8%) and high union of the tibial veins (737 limbs, 83%). The course variations included medial malposition (60 limbs, 7%), anterior rotation (11 limbs, 1%) and posterior rotation (4 limbs, 0.4%). Mapping the individual variations revealed regional differences in the pattern and frequency of the variations.

CONCLUSION

CT venography helps to confirm a high incidence of variations in the lower limb venous anatomy and it also revealed various positional venous anomalies in relation to the respective artery.

Femoral vein duplication: incidence and potential significance

Objective

The purpose of this study was to determine the prevalence of femoral vein duplication and the incidence of bilateral anomalies in a normal cohort of patients presenting with varicose veins.

Methods

Two hundred and forty patients underwent bilateral lower limb deep venous ultrasound examination with particular attention to the femoropopliteal segment.

Results

The incidence of femoral vein duplication was 41%. Of the 140 people with femoral vein duplications, 60 (42%) were bilateral and 80 (57%) were unilateral.

Conclusion

Femoral vein duplication is a common anatomical variant of the lower limb deep venous system. Ultrasound in skilled and experienced hands with the latest ultrasound units can readily demonstrate this venous anomaly on a consistent basis.

Prevalence of lower extremity venous duplication

PURPOSE

This retrospective study was performed to determine the prevalence of lower extremity venous duplication using duplex ultrasound in the patient population of a large urban medical center.

MATERIAL AND METHODS

The reports of all lower extremity venous ultrasound examinations performed at our institution between January 1, 2002 and December 31, 2002 were reviewed. Ultrasound examinations that were performed for purposes other than the detection of lower extremity deep vein thrombosis were excluded. The prevalence of duplication and its specific location were recorded. In addition, the prevalence of thrombus and its specific location were also recorded.

RESULTS

A total of 3118 exams were performed in 2664 patients. Of the 2664 patients, 2311 had only one examination performed during the study period; 353 patients had more than one examination performed. We found that 10.1% of patients (270/2664) had at least one venous segment duplicated and 5.4% of patients (143/2664) had a thrombus in at least one venous segment. There was a statistically significant difference in the prevalence of both duplication and thrombus with a change in venous segment. Only 0.4% of patients (11/2664) had thrombus within a duplicated segment. Of those who had more than one examination performed, 15.3% (54/353) had the same venous segment(s) seen on one examination but not another.

CONCLUSION

Lower extremity venous duplication is a frequent anatomic variant that is seen in 10.1% of patients, but it may not be as common as is generally believed. It can result in a false negative result for deep vein thrombosis.

A duplex scan-based morphologic study of the femoral vein: Incidence and patterns of duplication

The presence of femoral vein (FV) duplicity has potential influence in the misdiagnosis of deep vein thrombosis. Also, FVs are suitable vascular substitutes, especially in the substitution of infected prosthetic grafts. The objective of this study was to describe the prevalence, anatomic patterns and characteristics of FV duplicity in adult individuals by duplex scan examination. A total of 174 adult individuals were submitted to duplex-scan examinations of both lower limbs. Individuals with duplex signs of present or previous DVT or with poor quality duplex images were excluded from the investigation. The remaining group consisted of 157 individuals (94 females), with a total of 314 limbs studied. Along with the conventional duplex investigation sequence, the FV was scanned both in transversal and longitudinal views. The number, extension and diameter of FVs were documented. It was found that 173 limbs (55.1%) had duplicated FV. Duplicity in the whole femoral extension was noted in 82 (26.1%) limbs, and out of these only 28 (8.9% of the overall number) had accessory veins with a diameter approximate to (at least 75%) the main FV. Partial (distal or proximal) duplications were seen in 89 (28.3%) limbs. A third FV was present in 28 limbs. As a possible vascular substitute, 99.0% of the main FVs and 25.4% of the accessory veins presented diameters superior to 6 mm, a suitable value for iliac substitution. In conclusion, FV duplicity is frequent, and occurred in 55% of all limbs studied. However, complete extension duplicated veins with similar diameters was an uncommon condition, noticed in fewer than 10% of limbs.

Variations in lower limb venous anatomy: implications for US diagnosis of deep vein thrombosis

PURPOSE

To retrospectively review bilateral venograms free of thrombus to evaluate the frequency and types of variations seen in venous anatomy.

MATERIALS AND METHODS

A retrospective review of 404 bilateral (808 limbs) lower limb venograms obtained from medical patients participating in a thromboprophylaxis clinical trial and found to be free of thrombus was performed. Venograms were evaluated according to predetermined criteria for the presence of duplication of vessels and inter- and intraindividual variations in venous anatomy. Variations were assessed with analysis of variance and chi2 tests.

RESULTS

Two vessels were seen in the popliteal fossa on 337 (42%) of 808 venograms, and 41 (5%) were true duplicated popliteal veins. There were 253 (31%) duplicated superficial femoral veins (SFVs), with 12 (1.5%) being complex duplicated systems. Of 265 duplicated SFVs, 138 (52%) began in the midthigh region and 80 (30%), in the adductor canal region. The duplicated vessel was medial to the main SFV in 122 (46%), lateral in 131 (49%), and both (ie, triplications) in 12 (4.5%). The length of the duplicated SFV ranged from 1 to 35 cm; 6-15 cm was the most common length in 162 (62%) SFVs. There was no significant association between the incidence of anatomic variations and age or sex (P >.1). The presence of multiple vessels in one leg was strongly correlated with the probability of occurrence in the other leg (P <.001).

CONCLUSION

Variations in lower limb venous anatomy are common and have important implications for the US diagnosis of deep vein thrombosis.

Duplicated popliteal and superficial femoral veins: incidence and potential significance

BACKGROUND

Duplication of the popliteal and superficial femoral veins (PV, SFV) is a normal variant previously reported in up to 25% of limbs. Little clinical significance, however, has been attributed to this apparently common anomaly. The present study was designed to determine the incidence of duplications in individuals presenting for venous incompetence studies, and whether their presence could, in theory, act as a predisposing factor to deep venous thrombosis (DVT) formation.

METHODS

Duplex ultrasound examinations were performed in which venous duplications were actively searched for and recorded. The diameters of both limbs of any duplicated system and the single vessel immediately distal to it were recorded. Using these measurements, the changes in total cross-sectional area (CSA) associated with these anomalies were calculated. In addition, with the knowledge that the volume flow rate must remain constant, the velocity changes associated with such systems were calculated.

RESULTS

A total of 248 limbs from 177 patients was scanned. Duplications were found in 39 (15.7%) of these limbs. Of these, 30 limbs (77%) involved only the SFV, seven (18%) involved both the SFV and PV, and two (5%) involved only the PV. Short-segment SFV duplications were used to calculate the percentage change in total CSA and therefore blood flow velocities. Of the 13 (33%) suitable for such calculations, and calculating for each individual duplicated system, a mean increase in the vessel's total CSA of 42%, which corresponded to a theoretical decrease in blood flow velocity of 36%, was found.

CONCLUSION

The present study confirms the significantly high incidence of duplications of the PV and SFV and raises the possibility of the potential for DVT formation secondary to changes in flow velocities.

Thrombosis in a duplicated superficial femoral vein in a patient with haemophilia A

Venous thrombosis is a very rare occurrence in patients with haemophilia A. We report the case of a haemophiliac in whom initially a calf haematoma was suspected, but neither this nor deep venous thrombosis (DVT) could be confirmed on ultrasound scanning. Subsequently, a high segment venous thrombosis was diagnosed by venography in a portion of a duplicated superficial femoral vein. Treatment with factor VIII (FVIII) and low molecular weight heparin led to a successful resolution. The only other case we have been able to find in the literature occurred during FVIII replacement therapy, which was not the situation with our patient.

Imaging evaluation of suspected pulmonary embolism

Venous thromboembolism (VTE) is a common disorder that is difficult to diagnose clinically but carries significant morbidity and mortality if untreated. Additionally, although demonstrated to be of benefit in cases of proven deep vein thrombosis (DVT) and pulmonary embolism (PE), anticoagulation therapy is not without risk. Because the clinical exam is known to be unreliable for the detection of both DVT and PE, many imaging modalities have been used in the diagnostic imaging algorithm for the detection of VTE, including chest radiography, ventilation/perfusion (V/Q) scintigraphy, pulmonary angiography, and recently, spiral computed tomography (CT) and magnetic resonance imaging (MRI). Chest radiographic findings in acute PE include focal oligemia, vascular enlargement, atelectasis, pleural effusions, and air space opacities representing pulmonary hemorrhage or infarction. The chest radiograph can occasionally be suggestive of PE but is more often nonspecifically abnormal. The main use of the chest radiograph in the evaluation of suspected PE is to exclude entities that may simulate PE and to assist in the interpretation of V/Q scintigraphy. Lower extremity venous compression ultrasonography (CU) is both sensitive and specific for the diagnosis of femoropopliteal DVT, and the value of negative CU results has been established in outcomes studies. However, the reliability of CU for the detection of isolated calf vein thrombosis is not well established, and the clinical significance of such thrombi is debatable. Additional methods such as color and spectral Doppler analysis are also useful in the diagnostic evaluation of DVT but are best considered as adjuncts to the conventional CU examination rather than as primary diagnostic modalities themselves. Compression ultrasonography and Doppler techniques are useful in the evaluation of suspected upper extremity DVT; spectral Doppler waveform analysis is particularly useful to assess for the patency of veins that cannot be directly visualized and compressed with conventional gray-scale sonography. V/Q scintigraphy has been the initial modality obtained in patients suspected of PE for a number of years. Although many studies have investigated the role of V/Q scintigraphy in the evaluation of VTE, the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study has provided the most useful information regarding the utility of V/Q scintigraphy in this setting. A high probability scan interpretation is sufficient justification to institute anticoagulation, and a normal perfusion scan effectively excludes the diagnosis of PE. A normal/near normal scan interpretation also carries a sufficiently low prevalence of angiographically proven PE to withhold anticoagulation. Although the prevalence of PE in the setting of low probability scan interpretations is low and several outcomes studies have demonstrated a benign course in untreated patients with low probability scan results, patients with inadequate cardiopulmonary reserve do not necessarily have good outcomes. Such patients deserve more aggressive evaluation. Patients with intermediate probability scan results have a 20% to 40% prevalence of angiographically proven PE and thus require further investigation. The radionuclide investigation of DVT includes such techniques as radionuclide venography and thrombus-avid scintigraphy. Although these methods have not been as thoroughly evaluated as CU, studies thus far have indicated encouraging results, and further investigations are warranted. Pulmonary angiography has been the gold standard for the diagnosis of PE for decades. Studies have indicated that angiography has probably been underutilized by referring physicians for the evaluation of suspected PE, likely because of the perception of significant morbidity and mortality associated with the procedure. (ABSTRACT TRUNCATED)