Is variation in posterior tibial veins a risk factor for deep-vein thrombosis?

INTRODUCTION: This study proposes variations in the posterior tibial vein as one of the risk factors for deep-vein thrombosis. Understanding the anatomical classification of the posterior tibial vein would guide the antegrade approach of catheter-directed thrombolysis. MATERIALS AND METHODS: One hundred thirty-four legs from Korean and Thai cadavers were dissected. The posterior tibial veins were classified into four types according to the number of proximal and distal veins. RESULTS: The most common type was type Ia (64/134), followed by type IIa (28/134), type Ib (24/134), and type IIb (16/134). CONCLUSIONS: The anterior tibial and fibular veins had exactly two paired veins; however, the posterior tibial vein had many variations. We assume that patients with type IIb and IIa have a higher risk of thrombosis and hidden symptoms due to collateral formation. Additionally, the classification of the posterior tibial vein and dividing into proximal and distal posterior tibial vein would help practitioners predict the course and guide the application of catheter-directed thrombolysis.

Proximity of the Neurovascular Bundle During Posterior-Lateral Meniscal Repair: A Comparison of the Transpatellar, Anteromedial, and Anterolateral Portals.

PURPOSE: To compare the neurovascular proximity of the transpatellar portal with that of the medial and lateral portals and to determine the safe penetration depth for an all-inside device for use on the posterior horn lateral meniscus. METHODS: Dissection of the popliteal fossa was performed in 10 cadaveric knees to identify all structures. Arthroscopy was performed using penetration depths of 10, 12, 14, and 16 mm with the all-inside system through the anteromedial, anterolateral, and transpatellar portals. Penetrations were made 5 and 10 mm lateral to the posterior horn root at the meniscocapsular junction. Needle-tip distances were measured from the popliteal artery and vein, tibial nerve, and common peroneal nerve. RESULTS: Among 240 trials, the average distance to the popliteal neurovascular bundle using the medial, transpatellar, and lateral approaches was 6.9 mm, 6.5 mm, and 3.1 mm, respectively. The transpatellar-portal needle had a larger distance from the neurovascular bundle than the lateral portal (P = .001), with no statistical difference compared with the medial portal (P = .58). Compared with the position at a 10-mm distance from the root, the position at a 5-mm distance from the root was closer to the neurovascular bundle in all approaches (P = .001). The transpatellar approach set to 14 mm had a 5% rate of capsular underpenetration and 10% rate of gastrocnemius penetration. The transpatellar and medial portals had no neurovascular penetrations, whereas the lateral approach had a 14% rate of penetration (P < .05). CONCLUSIONS: The transpatellar portal and anteromedial portal are in less proximity to the neurovascular bundle compared with the anterolateral portal for all-inside meniscal repair of the posterior horn lateral meniscus. Low rates of neurovascular penetration, gastrocnemius muscle penetration, and capsular underpenetration occurred with a depth setting of 14 mm. CLINICAL RELEVANCE: This study shows the utility of medial and transpatellar portals when using all-inside devices to repair posterior horn lateral meniscal tears and neurovascular proximity based on penetration depth.

Human Femoral Vein Diameter and Topography of Valves and Tributaries: A Post Mortem Analysis.

The femoral vein (FV) is a clinically important vessel. Failure of its valves can lead to chronic venous insufficiency (CVI) with severe manifestations such as painful ulcers. Although they are crucial for identifying suitable implant sites for therapeutic valves, studies on the topography of FV tributaries and valves are rare. Moreover, the femoral vein diameter (FVD) must be known to assess the morphometric requirements for valve implants. To reassess the anatomical requirements for valve implants, 155 FVs from 82 human corpses were examined. FVDs and tributary and valve topographies were assessed using a laboratory straightedge. The FVD increased from 6 mm in the distal femoropopliteal vein to 11 mm in the iliofemoral vein proximal to the saphenofemoral junction (SFJ). Diameters were significantly bigger in males than females. Height correlated positively with FVD. Distal to the SFJ, within a distance of 38 cm, one to eight valves were present. Up to two valves were present within 10 cm proximal to the SFJ. Individual tributary and valve topography must be considered to ensure appropriate design and successful implantation of a venous valve for CVI therapy in the FV. A suitable implant site would be proximal to the SFJ via an infrainguinal transfemoral access. Clin. Anat. 31:1065-1076, 2018. © 2018 Wiley Periodicals, Inc.

Anatomic variations of lower extremity venous system in varicose vein patients: demonstration by three-dimensional CT venography.

Background Understanding the anatomy of the lower extremity veins is essential for successful varicose vein treatment. Computed tomography (CT) venography may be used to obtain a comprehensive overview and detailed information regarding this. Purpose To describe anatomic variations of the lower extremity venous system in patients with varicose veins, using three-dimensional (3D) CT venography. Material and Methods A total of 810 limbs in 405 patients with suspected varicose veins were prospectively referred to undertake CT venography and included in our study population retrospectively. The CT venography images were evaluated by consensus of two cardiovascular radiologists. Anatomical variations of the lower extremity venous system and their incidence were analyzed. Specifically, the number of tributaries at saphenofemoral junction, relative location of the great saphenous vein (GSV) with respect to the common femoral artery bifurcation, pattern of saphenopopliteal junction, and end of thigh extension from the small saphenous vein (SSV) were assessed. Results The most frequent number of tributaries joining the GSV was four (44.4%, 360/810). Only 0.7% (6/810) of the limbs demonstrated unusual location of the GSV between the bifurcated superficial and deep femoral arteries. The most common pattern of veins at the saphenopopliteal junction was a larger caliber of saphenopopliteal junction than thigh extension from SSV (43.8%, 355/810), end of which joining the femoral vein directly (41.0%, 288/703). Conclusion CT venography with 3D reconstruction can be used to understand the anatomy of lower extremity veins and how their variations contribute to varicose veins.

Location of the Neurovascular Bundle of the Knee during Flexed and Extended Position: An MRI Study.

Background: The popliteal vessels and nerve are the structures most at risk during surgery of the posterior knee compartment. Common procedures that could interfere with or otherwise affect these structures include synovectomy, meniscal repair, proximal tibial osteotomy, knee replacement and fixation around the knee joint. Magnetic resonance imaging (MRI) can be used to locate the neurovascular structures from the posterior bony landmark. MRI imaging is routinely studied in the extended knee, but surgery of the posterior knee compartment is most often performed with the knee in a flexed position. Objective: The aim of this study was to investigate the location of the posterior neurovascular bundle relative to the posterior aspect of the femur, tibia, and posterior cruciate ligament during fully extended knee position and 90-degree flexed knee position using MRI. Material and Method: MRI images of 26 knees were obtained from 25 patients. Ten left knees, 14 right knees, and 1 bilateral knees were obtained from 18 males and 7 females. Axial plane and sagittal plane studies were used to measure the shortest distance of the popliteal artery, popliteal vein, and tibial nerve to the posterior bony aspect of the knee and the posterior cruciate ligament using a digital ruler tool from the PACS X-ray system. Measurement was performed at joint line level, 1 cm above joint line level, and 1 cm below joint line level in the fully extended knee position and in the 90-degree flexed knee position. At the joint line level, the mediolateral distance of the popliteal artery, popliteal vein, and tibial nerve to the posterior cruciate ligament were also measured. Results: At 1 cm above joint line level, mean anteroposterior (AP) distance from the distal femoral condyle to the popliteal artery, popliteal vein, and tibial nerve was 1.83+3.35 mm, 6.44+4.55 mm and 10.29+4.41 mm for full knee extension, and 15.60+5.01 mm, 20.63+4.62 mm and 26.24+7.70 mm for 90-degree knee flexion, respectively (p<0.001). At joint line level, mean AP distance from the posterior tibial cortex to the popliteal artery, popliteal vein, and tibial nerve was 5.43+3.22 mm, 8.75+3.72 mm and 13.10+4.15 mm for full knee extension, and 11.64+5.48 mm, 17.59+6.53 mm and 21.52+10.67 mm for 90-degree knee flexion, respectively (p<0.001). At 1 cm below joint line level, mean AP distance from the posterior tibial cortex to the popliteal artery, popliteal vein, and tibial nerve was 1.98+1.95 mm, 4.26+2.74 mm and 8.66+3.85 mm for full knee extension, and 6.91+2.86 mm, 12.34+5.23 mm and 16.58+9.22 mm for 90-degree knee flexion, respectively (p<0.001). At joint line level, mean distance from the posterolateral border of the PCL to the popliteal artery, popliteal vein, and tibial nerve was 11.12+2.62 mm, 11.30+4.05 mm and 15.14+5.05 mm for full knee extension, and 19.89+5.67 mm, 23.87+6.96 mm and 29.41+10.72 mm for 90-degree knee flexion, respectively (p<0.001). Conclusion: During 90-degree knee flexion, the neurovascular structures move posterolaterally, as compared to fully extended knee position at joint line level and 1 cm above and below joint line level. To prevent neurovascular injury during surgery, surgeons should avoid or be cautious during blind penetration of the midline joint capsule and 90 degree flexed knee position increases the distance of the neurovascular bundle away from the posterior bony aspect.

Anatomical and physiological changes in the venous system of lower limbs in pregnant women and findings associated with the symptomatology.

PURPOSE: Quantify the volume and diameter of veins in the lower limbs of primigravidae and associate the presence of venous signs and symptoms with the vascular measurements. METHODS: A cross-sectional study assessed 64 lower limbs of 32 healthy women of whom 16 were primigravidae between 22 and 36 weeks pregnant, and 16 nulligravidae. The women were submitted to physical assessment, air plethysmography and vascular ultrasound. The volumes and diameters of the main veins in the lower limbs were compared between pregnant and non-pregnant women. In the group of pregnant women, the attempt was also made to associate such measurements to the presence of vascular signs and symptoms. RESULTS: The average venous volume of the lower limbs (110.1 ± 30.2 and 94.7 ± 27.3 mL; p = 0.036), as well as the diameters of the common femoral (12.72 ± 2.27 and 10.14 ± 1.24 mm; p < 0.0001), saphenous (4.81 ± 1.15 and 3.55 ± 0.98 mm; p < 0.0001) and popliteal (6.87 ± 1.68 and 5.36 ± 1.07 mm; p < 0.0001) veins were, respectively, greater in the pregnant women compared with the control group. In pregnant women with venous stasis symptoms, a venous diameter of the saphenous vein compared to those without no symptoms (5.05 ± 1.19 and 4.09 ± 0.70 mm; p = 0.011) was noted. CONCLUSIONS: Anatomical and functional changes in the venous system during pregnancy were detected by the air plethysmography and the vascular ultrasound in primigravidae. In pregnant women, the presence of venous stasis symptoms found an anatomical and functional substrate detected in the differences in diameter of the saphenous vein.

Techniques of popliteal nerve regional anesthesia.

Regional anesthesia for blockade of the sciatic nerve in the popliteal fossa is a useful adjunct to pain management in the perioperative setting for foot and ankle surgeons. The present tip aimed to provide a review of the relevant anatomy and technique for popliteal nerve block from the posterior and lateral approaches and to provide discussion and images of the use of peripheral nerve stimulation and ultrasound guidance as adjuvant methods to improve efficacy and reproducibility.

Variations in popliteal fossa venous anatomy: implications for diagnosis of deep-vein thrombosis.

BACKGROUND: To retrospectively review the bilateral venous system within the popliteal fossa to evaluate the types of variations and their frequency seen in venous anatomy. MATERIALS AND METHODS: During routine dissection of formalin-fixed cadavers, a retrospective review of 32 bilateral (64 limbs) lower limbs obtained from adult donors was performed. Deep veins present in the popliteal fossa were evaluated according to predetermined criteria for the presence of duplication of vessels and interindividual variations in venous anatomy. RESULTS: More than one deep venous vessel was seen in the popliteal fossa in 20 (31.3%) of 64 limbs. In 12 (18.7%) cases there was a high (just below the level of the adductor hiatus) origin of the popliteal vein: from 2 tributaries in 10 (15.6%) and 3 tributaries in 2 (3.1%). In 5 (7.8%) cases true duplicated popliteal veins were observed. There were also 3 (4.7%) cases, including one bilateral, of persistent sciatic vein. CONCLUSIONS: Variations in popliteal fossa venous anatomy are common and have important implications for the diagnosis of deep vein thrombosis.

[The application of popliteal vein anatomy study and valve construction procedure].

OBJECTIVE: To analyze anatomy data of popliteal veins (PV), with the purpose of selection of popliteal venous valves construction segment via venography, and to evaluate the surgical results. METHODS: From February 1998 to November 2010, after analyzing the popliteal vessel anatomy data of 39 limbs and related phlebography research of 862 cases, 102 patients (69 male and 33 female patients, aged from 48 to 71 years, mean 59 years) with severe deep venous insufficiency were selected for popliteal venous valve construction procedures. Doppler ultrasound, continuous dynamic venography, and intraoperative venous pressure measurements were used to assess the hemodynamic changes pre- and postoperatively. Venous clinical severity score (VCSS) were used to evaluate long-term results of deep venous valve construction procedures. RESULT: In the 102 patients, 93.7% patients had one pair of valves in popliteal vein (PV), locating in the distal 1/3 segment of PV, with gastrocnemius veins (GV) joining with PV above PV valves. Postoperative blood flow volume of the PV was significantly higher than the preoperative volume (732.3 ml/min vs. 150.2 ml/min, t = 8.979, P < 0.001). The proximal pressure was significantly lower than the distal pressure ((12 ± 3) cm H(2)O vs. (15 ± 3) cm H(2)O, 1 cm H(2)O = 0.098 kPa, t = 8.049, P < 0.001). VCSS score was significantly lower after the surgery ((34 ± 15) cm H(2)O vs. (41 ± 14) cm H(2)O, t = 59.780, P < 0.001). Pre- and postoperative hemodynamic changes and VCSS scores were statistically significant (9.3 ± 1.9 vs. 1.8 ± 1.0, t = 59.780, P < 0.001). Mean follow-up were 8.9 years with an ulcer recovery rate of 96.3%, and a 3.7% ulcer recurrent rate. CONCLUSIONS: Popliteal vessel anatomy study and venography research provide critical information for the PV valve construction part selection, which stayed proximal to the communications of GV and PV. Restoration of gastrocnemius pump function and satisfactory long-term efficacy are received after valve construction.

Number and location of venous valves within the popliteal and femoral veins: a review of the literature.

Although deep venous insufficiency is common and important, the anatomy of deep vein valves is poorly understood. The aim of this study was to investigate the location, number and consistency of venous valves in the femoral and popliteal veins in normal subjects. A detailed literature search of PubMed was performed. Abstracts and selected full text articles were scrutinised and relevant studies published between 1949 and 2010 reporting anatomical details of deep vein valves were included. From 7470 articles identified by the initial search strategy, nine studies with a total of 476 legs were included in this review. All studies were cadaveric and subjects ranged from stillborn fetuses to 103 years of age. Studies suggested that femoral veins contain between one and six valves, and popliteal veins contain between zero and four valves. Deep vein valves were consistently located in the common femoral vein (within 5 cm of the inguinal ligament), the femoral vein (within 3 cm of the deep femoral vein tributary) and in the popliteal vein near the adductor hiatus. Valves are consistently located at specific locations in the deep veins of the leg, although there is often significant variability between subjects. Further anatomical and functional studies using new imaging modalities available should target these areas to identify whether certain valves play a more important role in venous disease. This may guide us in the development of new treatment options for patients with deep venous disease.

Inside-out medial meniscus suture: an analysis of the risk of injury to the popliteal neurovascular bundle.

PURPOSE: To assess the risk of damage to the popliteal neurovascular structures when inserting the needle through the posterior aspect of the knee during inside-out suture of the posterior horn of the medial meniscus. METHODS: The first stage of our study consisted of simulating a virtual meniscal suture during magnetic resonance imaging by tracing a line from 3 different points (located medially [MP], centrally [CP], and laterally [LP] to the patellar tendon) to the posterior horn of the medial meniscus. This procedure was undertaken both at rest and with valgus stress. The next phase involved the suture of the posterior horns of medial menisci taken from cadaveric specimens, the needle being inserted through 3 separate locations (again located medially [MP], centrally [CP], and laterally [LP] to the patellar tendon). Finally, the distance from each suture thread to the aforementioned neurovascular bundle was measured. RESULTS: During the magnetic resonance imaging study, the measured distances at rest were 26.4 mm for MP, 28.8 mm for CP, and 31 mm for LP, whereas those recorded with valgus stress were 21.7 mm for MP, 23.6 mm for CP, and 26 mm for LP. In the second phase of the study (cadaveric specimen suture), the distances obtained were 22.6 mm for MP, 27.6 mm for CP, and 33 mm for LP. CONCLUSIONS: Our results indicate that when the needle is inserted through the 3 points investigated into the posteromedial region of the knee (10 mm from the posterior horn of the internal meniscus) during inside-out suture, it is far enough from the popliteal neurovascular bundle for the maneuver to be performed with a reasonable safety margin. However, this margin can be increased further still if the needle is inserted into the joint through a point located laterally to the patellar tendon. CLINICAL RELEVANCE: Inside-out suture performed 10 mm from the posterior horn of the internal meniscus through the portals studied offers a sufficient margin of safety to avoid damage to the popliteal neurovascular bundle.

The anatomy of the small saphenous vein: fascial and neural relations, saphenofemoral junction, and valves.

PURPOSE: Varicose veins are a frequent burden, also in the small saphenous system. Yet its basic anatomy is not described consistently. We therefore investigated the fascial and neural relationships of the small saphenous vein (SSV) as well as the frequency and position of valves and the different junctional patterns, also considering the thigh extension. MATERIALS AND METHODS: We dissected the legs of 51 cadavers during the regular dissection course held in winter 2007 at Innsbruck Medical University, with a total of 86 SSVs investigable proximally and 94 SSVs distally. RESULTS: A distinct saphenous fascia is present in 93 of 94 cases. It starts with a mean distance of 5.1 cm (SD 1.2 cm) proximal to the calcaneal tuber, where the tributaries to the SSV join to form a common trunk. The neural topography at the level of the gastrocnemius muscle's origins shows the medial sural cutaneous nerve in 88% medially and in 12% laterally to the SSV, the tibial nerve in 64% medially and in 36% laterally, and the common fibular nerve in 98% medially and in 2% laterally to the vein. The saphenopopliteal junction (SPJ) resembled in about 37% type A (UIP-classification), 15% type B, and 24% type C. A total of 17% of specimens showed a venous web or star at the popliteal fossa and 6% had a doubled junction. A thigh extension could be demonstrated in about 84%. A most proximal valve was present in only 94% at a mean distance of 1.2 cm (SD 1.4 cm) to the SSVs orifice. A consecutive distal valve was only present in 65% with a mean distance of 5.1 cm (SD 2.3 cm). CONCLUSION: Two fascial points or regions can be described in the SSVs' course and its own saphenous fascia is demonstrated macroscopically in almost all cases. The neural topography is highly individual. The SPJ is highly individual where we found hitherto unclassified patterns in a remarkable number of veins. Venous valves are not as frequent as we supposed them to be. Furthermore, not all most proximal valves seem to be terminal valves.

Valve distribution of the popliteal vein: A structural basis for deep venous thrombosis?

OBJECTIVE: To describe the relationship between number and distribution of valves. METHODS: Sixty-six popliteal vein specimens were used for the study after routine dissection at the Department of Human Anatomy, University of Nairobi. The extents of the popliteal vein were identified at the adductor hiatus and soleal arch, cut at these points and then longitudinally sliced open. The number and distribution of valves were then recorded. Data were presented using photomacrographs and tables. RESULTS: The median number of valves was 1 (mean 0.8; range 0-2), with the lower part of the popliteal vein as the most consistent valve position. Most striking was the valve absence noted in 27 (41%) of the veins. CONCLUSION: These findings suggest that a significant proportion of popliteal veins do not have valves thus providing a credible structural link that may predispose the popliteal vein to deep venous thrombosis in the study population.

Axial transformation of the profunda femoris vein: formation, relations and course in a cadaveric specimen.

When the superficial femoral vein is obstructed by thrombosis, the profunda femoris vein provides an important collateral pathway, transforming into the axial vein of the lower limb. When operating on a transformed axial vein, a surgeon should be aware of the formation, the relations and the course of the vein. A precise description of these anatomical features is not feasible on the basis of ultrasound, venographic or surgical study but only from anatomical studies. We present a case of axial transformation of the profunda femoris vein found in a cadaver, focusing on the anatomical features of the transformed axial vein.

The blood supply of the common peroneal nerve in the popliteal fossa.

We investigated the blood supply of the common peroneal nerve. Dissection of 19 lower limbs, including six with intra-vascular injection of latex, allowed gross and microscopic measurements to be made of the blood supply of the common peroneal nerve in the popliteal fossa. This showed that a long segment of the nerve in the vicinity of the fibular neck contained only a few intraneural vessels of fine calibre. By contrast, the tibial nerve received an abundant supply from a constant series of vessels arising directly from the popliteal and posterior tibial arteries. The susceptibility of the common peroneal nerve to injury from a variety of causes and its lack of response to operative treatment may be explained by the tenuous nature of its intrinsic blood supply.

Harvesting the superficial femoral vein as an autograft.

The superficial femoral-popliteal vein (SFPV) is an excellent conduit for reconstructing large arteries and veins. Herein we describe the anatomy, preoperative evaluation, and exposure technique of the SFPV. Harvesting the SFPV from the level of the knee joint to the confluence with the profunda femoris vein is associated with minimal mid- and late-term venous morbidity. These vein grafts have proved to be durable conduits, particularly in the aortofemoral position.

Technical note: compression stockings and posture: a comparative study of their effects on the proximal deep veins of the leg at rest.

Graduated compression stockings have been shown to reduce the incidence of deep venous thrombosis. While they are thought to act primarily by increasing venous flow velocity, their mode of action remains uncertain. Doppler ultrasound was employed to study the relative effects of three types of support stocking on the deep venous diameter, flow velocity and pulsatility in 10 non-pregnant female subjects. In addition, the effect of altered posture on the same parameters was assessed. Significant effects of the graduated stockings were found at the level of the popliteal vein, where a reduction in both the diameter and the amplitude of respiratory phasicity was recorded (p < 0.05). No significant increase in flow velocities was recorded. Adopting the left lateral position significantly increased flow velocity in the right common femoral vein (p < 0.05). The application of stockings in this position produced no additional increase in flow velocities, but did alter the amplitude of respiratory phasicity. These data do not support the widely held view that graduated compression stockings increase flow velocities at rest. Adopting a lateral recumbent position significantly increases flow velocity in the non-dependent leg.

[Superficial veins of the leg]. / Les veines superficielles du membre inférieur.

This clinical work studies the normal pattern of the saphenous veins, their main variations with a short embryological reference. Some pathological cases are described; the perforator veins are very important; the role of the valves at the groin is emphasized.

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.