4 – Investigations
Venous obstruction
Assessment of venous obstruction with air plethysmography and duplex ultrasound
F. Lurie / USA
This study combines air plethysmography (APG) and duplex ultrasound (US) in patients with deep venous obstruction. The study included 25 patients with deep vein obstruction (10 iliac and 15 femoral) and a control group of 25 healthy volunteers studied with both APS and US. The segmental distribution of the flow was defined as a fraction of the total volume outflow contributed by each of the three veins (superficial femoral vein SFV, profunda femoral vein [PFV], great saphenous vein [GSV]) expressed in percent.
APG is a good test to determinate iliac vein occlusions, but is not effective in femoral vein occlusions. In healthy volunteers, SFV contributes 40% to 60%, PFV 20% to 30%, and GSV 10% to 20% to the total outflow. In the presence of SFV occlusions, the GSV flow increases to 80% of total flow, with no changes in PFV flow. It appears that in the case of SFV occlusions, GSV flow makes an important contribution to venous return. The contribution of PFV is these cases seems minor.
High peak reflux velocity in the proximal deep veins is a strong predictor of advanced postthrombotic sequelae
T. Yamaki, M. Nozaki, H. Sakurai, M. Takeuchi, K. Soejima, T. Kono / Japan
The presence of reflux in the deep venous system after an acute deep vein thrombosis is considered to contribute to the development of advanced postthrombotic syndrome. The aim of this study was to determine the ultrasound parameters reflecting the progression of PTS. The study included 131 limbs (130 patients) for which there was complete 6-year follow-up after an acute DVT. The patients were studied by means of ultrasound at 2 and 6 years. The ultrasound parameters analyzed at the popliteal vein (VP) and femoral vein (FV) were vein diameter, peak reflux velocity (PRV), reflux time (RT), and the total refluxed volume. The patients were divided into two groups depending on venous insufficiency severity measured by CEAP score: group I (C0 to C3) and group II (C4 to C6).
There were 98 patients in group I and 33 in group II. The frequency of venous reflux was significantly higher in group II, without differences in venous occlusion between the two groups. The proportion of FV and PV incompetence was higher in group II. There was no between-group difference in RT. Fifty-eight per cent of group II patients developed advanced symptoms of PTS during follow-up. Statistical analysis demonstrated that PRV>25.4 cm/s in PV and PRV>24.5 cm/s were strong predictors of advanced CVI.
In conclusion, PRV in patients with deep vein thrombosis is an independent predictor of the development of chronic venous insufficiency.
The utility of quantitative calf muscle near-infrared spectroscopy in the follow-up of acute deep vein thrombosis
T. Yamaki, M. Nozaki, H. Sakurai, M. Takeuchi, K. Soejima, T. Kono / Japan
The study was designed to examine venous segments in terms of occlusion, partial recanalization, and total recanalization with the application of quantitative calf muscle near-infrared spectroscopy (NIRS). The NIRS-derived calf venous blood filling index (HHbFI), calf venous ejection index (HHbEI), and the venous retention index (HHbRI) were assessed as markers of occlusion, partial recanalization, and total recanalization.
A total of 78 limbs with an acute deep vein thrombosis ( DVT) involving 156 anatomic segments were evaluated with duplex scan and NIRS.
At 1 year, the HHbFI in POPV reflux patients was significantly higher than in those with resolution (0.19±0.14, 0.11±0.05, P=0.009, respectively). Similarly, there was a significant difference in the HHbRI between the two groups (3.08±1.91, 1.42±1.56, P=0.002, respectively). In patients with femoral vein occlusion, the value of HHbRI was significantly higher than in those with complete resolution (2.59±1.50, 1.42±1.56, P=0.011, respectively).
Calf veins showed more rapid recanalization than proximal veins. NIRS-derived HHbFI and HHbRI could be promising markers of venous function during followup in acute DVT. Thus physicians may detect patients who require much longer follow-up studies.
Changes in the outpatient evaluation of deep venous thrombosis
M.C. Dalsing / USA
Currently, two main diagnostic approaches exist for patients with suspected DVT. Serial proximal compression ultrasonography (CUS), which is mostly used in North America, and which when negative has to be repeated one week later when scanning is not performed below the knee. However, a negative single complete (proximal and distal) ultrasonography has been shown to safely rule out the diagnosis of DVT. Scanning proximal to the knee repeating the CUS one week later is costly and time-consuming. This has led to the use of the D-dimer test as part of the diagnostic algorithms. D-Dimer testing is useful in excluding DVT (negative predictive value >95%), thereby reducing the need for duplex scanning in 39% of patients as demonstrated by a randomized controlled study (Wells et al, NEJM 2003). This strategy has proven effective and cost-effective.
Dalsing et al. propose the following approach. Patients with a high clinical probability of DVT as assessed by the Wells’ score (Wells et al. Lancet 1997) undergo a full duplex examination. Patients with a low or intermediate clinical probability undergo a D-dimer test and, if positive, proceed to a full duplex scan. If negative, they are left untreated. During off hours, patients in whom a CUS is required receive a single injection of LMWH while awaiting the ultrasonic diagnostic test. However, the safety and cost-effectiveness of this latter strategy remains to be formally validated.1,2
References
1. Wells PS, Anderson DR, Rodger M, et al. Evaluation of D-Dimer in the Diagnosis of Suspected Deep-Vein Thrombosis. N Engl J Med. 2003;349:1227-1235.
2. Wells PS, Anderson DR, Bormanis J, et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet. 1997;350:1795-1798.
Varicose veins
The evaluation of vein filling index of air plethysmography for type of varicose and lower-limb varicose vein treatment
M. Ojiro, S. Sane, S. Nakajima, K. Ehi, I. Omoto, T. Kuwahata / Japan
Aim: Although treatments of varicose veins include stripping sclerotherapy (foam) with high ligation, sclerotherapy only, and compression stockings, in Japan the main therapies are stripping (ST) and sclerotherapy with high ligation (LiG-SC). However, evaluation of these two therapies has been controversial. So, we studied the vein filling index (VFI) of air plethysmography (APG) and the clinical effects of ST and LiG-SC.
Methods: VFI was measured in 40 limbs of the ST group and 117 limbs of the LiGSC group before and after treatment of varicose veins. VFI and improvement in VFI were evaluated according to the method of treatment (ST vs LiG-SC), the number of ligations (saphenofemoral junction, Dodd, Boyd’s perforation, and other incompetent perforations), the type of varicose veins (saphenous major: 87 limbs, saphenous minor, and special type; 10 limbs), the severity of varicose veins (CEAP classification), and recurrence (18 limbs).
Results: In the ST group, the level of VFI decreased from 6.95 A (4.3 to 2.1 A) 1.4 mL/s after treatment. In the LiG-SC group, VFI was high in severe cases, but decreased to normal levels in almost all cases. The number of ligations increased in severe cases. VFI improved in all cases in the ST group, but was still abnormally high (above 2.2 mL/s) in 13 cases. In the LiG-SC group, VFI was abnormally high in 30 cases (25.0%): 43.8% of cases with under 3 ligations, 24.4% of cases with 4-6 ligations, and 21.7% of cases with above 7 ligations. VFI was not abnormal in saphenous vein minor and special types of varicose veins, and CEAP class 4-6 had a higher VFI than the other classes, but recurrence did not depend on VFI.
Conclusion: There was no significant difference in VFI improvement between the ST and LiG-SC groups. However, in the LiG-SC group, the number of ligations influenced the effect of VFI. Little improvement in VFI was noted for fewer than 3 ligations. The incidence of recurrence was higher in the LiG-SC group than in the ST group. The severity of varicose veins depended on the VFI, but the relation between recurrence and VFI is unknown.
Venous valve
Femoral vein valves: implantation of external support assessed by phleboscopy
G.M. Makhatilov, G.R. Askerkhanov, M.A. Kazakmurzaev, I.S. Ismailov / Russia Federation
The authors treated 28 limbs (24 patients) with primary venous valvular insufficiency in the superficial femoral vein by means of external implantation of Verdensky spirals. Phleboscopy identified 11 valves with elongated cusps and 16 with wide separation of cusps. Spirals restored valve competence in all 16 cases of cusp separation. The authors conclude that the technical success of the intervention depends on the type of valve insufficiency and the correct choice of spiral diameter.
Lymphedema
New concept regarding lymphatic malformationy
B.B. Lee, J. Laredo, D. Deaton, R. Neville / USA
The aim of this presentation was to enhance understanding of the two distinct conditions of extratruncular and truncular lymphatic malformations (LMs), clinically known as “cystic/cavernosus lymphangioma” and “primary lymphedema”.
Retrospective analysis was done on N=445 patients with predominantly LM lesions between 1995 and 2004. Lymphoscintigraphy was the most frequent diagnostic test for the primary lymphedema due to the truncular LM. CDT (complex decongestive therapy) or compression therapy or both were used to treat all cases of truncular LM.
Surgical therapy was added to the CDT to improve its clinical management. MRI and duplex ultrasonography were the basic tests for the lymphangioma due to extratruncular LM. Sclerotherapy with OK-432 and/or ethanol was the primary therapy, and surgical therapy was added mostly when the response to sclerotherapy was poor.
Appropriate identification of truncular or extratruncular LM is essential for safe management of either primary lymphedema or lymphangioma. A multidisciplinary approach in which surgical treatments are added to conventional treatment can improve the overall clinical management of both truncular and extratruncular LM.
Indocyanine green fluorescence imaging to detect lymphedema
I. Katoh, Y. Ogawa, H. Sogabe, H. Fujita, Y. Wakisaka, T. Kitagawa, M. Miwa, T. Shikayama / Japan
Pathological lymphatic dermal backflow is observed in patients who suffer from local lymphatic obstruction or segmental lymphatic incompetence. It is possible to investigate the superficial lymphatic system in swollen limbs with pathological skin backflow using indocyanine green (ICG) fluorescence. After ICG injection into the normal leg or palm, the lymphatic channels and superficial nodes appeared as a shining streams and spots with fluorescence from the side of injection to proximal parts of the limb. Real-time observation of the skin lymph transport visualizes superficial but not deep lymphatic channels and nodes.
For patients who suffer from lymphedema, an injection of ICG shows skin lymphatic capillaries spreading out in all directions from the point of injection. Reticulated patches of ICG are visible within one hour after injection and remain for several days in this group of patients. This phenomenon is never observed in the normal limb.
Patients with chronic venous insufficiency rarely present skin backflow. Further investigation and adaptation of this method to the needs of medical practice can provide a good and inexpensive tool which helps to differentiate lymphatic pathology from chronic venous insufficiency or to recognize the coexistence of both types of pathology.
