Ann R Coll Surg Engl 1998; 80: 388-393

Duplex scanning may be used selectively inpatients with primary varicose veins

P J Kent FRCSIConsultant Vascular Surgeon

M J Weston FRCRConsultant Radiologist

Departments of Vascular and Endovascular Surgery and Radiology, St James's University Hospital,Leeds

Key words: Duplex; Doppler; Varicose veins

Reflux was assessed using hand-held Doppler (HHD)and duplex scanning in 72 patients with primary,previously untreated varicose veins (108 limbs). Theaims of the study were (i) to compare the accuracy ofHHD assessment with duplex scanning, (ii) to assess

the benefit of tourniquet testing and (iii) to iden-tify patients who would benefit from a policy ofselective duplex scanning. HHD accurately assesses

the saphenofemoral junction (SFJ) and longsaphenous vein (LSV) reflux. HIHD assessment of thesaphenopopliteal junction (SPJ) reflux has a lowpositive predictive value. A high negative predictivevalue reflects absent SPJ reflux assessed using HHDaccurately. Tourniquet testing is not helpful. Selectiveduplex scanning oflimbs with suspected SPJ reflux, noidentifiable site of reflux or posterior thigh perforatorreflux on HDD (39% of limbs), would result in theappropriate surgical procedure being performed in102 (94%) limbs, excessive surgery in 5 (5%) limbs andinadequate surgery in only 1 (1%) limb. The use ofselective criteria for duplex scanning would reducethe workload of the vascular laboratory withoutcompromising patient care.

Varicose veins is a common clinical condition, affecting upto 25% of the adult female and 15% of the adult malepopulation (1). Because of the large numbers of patientsaffected by primary varicose veins, many surgeonsproviding treatment for these patients feel that it isneither feasible nor cost-effective to use duplex scanningon a routine basis, to determine the underlying site or sitesof reflux from the deep to the superficial veins (2).Treatment is planned on the basis of clinical examination,

with or without continuous wave hand-held Doppler(HHD) assessment, with duplex scanning and phlebo-graphy reserved for use in selected patients (2-4).Traditional clinical examination of patients with varicoseveins using the cough test, the tap test and the Brodie-Trendelenberg test, has been demonstrated to be lessaccurate than assessment using hand-held Doppler (5-8).The introduction of directional flow Doppler in the late1960s has improved the ability of the clinician toaccurately locate sites of reflux from the deep to thesuperficial veins (9).The identification of venous reflux and the localisation

of the site or sites of valvular incompetence using duplexscanning, is well established (10,11). This non-invasiveinvestigation has replaced phlebography as the 'goldstandard' in the assessment of venous reflux in many

centres. Recurrent varicose veins place a large economicand surgical burden on any healthcare system. Approxi-mately 20% of surgical procedures performed for thetreatment of varicose veins are carried out for recurrentdisease (12-14). The reasons commonly cited forrecurrence of varicose veins are inadequate initialassessment, inadequate surgery, neovascularisation andthe subsequent development of reflux from the deep to thesuperficial venous systems (12,13). The accurate identi-fication of sites of reflux from the deep to the superficialvenous systems at the initial presentation should allowmore accurate planning of therapeutic procedures andshould decrease the incidence of recurrence.The aims of this study were:

1 To determine the accuracy of hand-held Dopplerassessment of patients with primary, previouslyuntreated varicose veins compared with duplexscanning.

2 To assess the benefit, if any, of using tourniquettesting in these patients.

Correspondence to: Mr P J Kent, Department of Vascular andEndovascular Surgery, St James's University Hospital, BeckettStreet, Leeds LS9 7TF

Duplex scanning of varicose veins 389

3 To identify the subgroups of patients who wouldbenefit from a policy of selective duplex scanning.

Patients and methods

A total of 72 patients with primary varicose veins (108limbs) who had not undergone previous injectionsclerotherapy or surgical treatment were recruited totake part in this prospective study. Informed consent was

obtained from all patients. There were 20 males and 52females, median age 44.5 years (range 19-73 years).Hand-held Doppler assessment was performed through-

out this study by a consultant vascular surgeon (PJK) usinga hand-held Doppler with an 8 MHz probe (Multi-Dopplex, Huntleigh, HNE Diagnostics, Cardiff, UK).

In the standing position, the patient was asked toslightly flex the hip and the knee of the leg underinvestigation and to bear weight on the opposite leg. TheDoppler probe was placed over the saphenofemoraljunction (SFJ) and the calf compressed. Augmentedantegrade flow was determined after calf squeeze andthe presence of reflux on calf release was noted. Refluxlasting longer than 0.5 s was deemed significant (15). Theprobe was then placed over the long saphenous vein(LSV) at the level of the knee and again the presence ofreflux on release of calf compression was indicative ofreflux in the long saphenous vein. A standard phlebotomytourniquet (2.5 cm wide) was applied just below thesaphenofemoral junction and the process repeated. Withthe tourniquet in position, the presence of reflux in thegroin was taken to denote reflux in the superficial femoralvein (SFV) (16). The presence of sustained reflux over

the long saphenous vein at knee level was taken to beindicative of mid-thigh perforator (MTP) incompetence.The probe was then placed over the saphenopopliteal

junction (SPJ) at the level of the flexion crease of the knee.Augmentation of blood flow on calf compression and thepresence of reflux on release was noted. The tourniquetwas again applied below the site of insonnation and theprocedure repeated. The presence of reflux with thetourniquet in this position was taken to indicate poplitealvein (PV) reflux (16).Every patient underwent duplex scanning of the veins

of the lower limb, together with guided pulsed wave

spectral Doppler. Duplex imaging was carried outimmediately after HHD assessment as changes in thepattern of reflux can be expected to occur if there is a

prolonged period between assessments (17). The exami-nation was performed by a consultant radiologist (MJW),who was unaware of the results of HHD and tourniquetassessment.Duplex scanning was performed using a Siemens Q2000

machine (Siemens, Berlin, Germany), with 5 MHzcurvilinear probe. Deep venous patency was assessedwith the patient semi-recumbent, with the hip externallyrotated and the knee slightly flexed. The vein compressiontechnique was used to test for femoral and popliteal venouspatency, and colour Doppler for tibial vein pair patency.Venous incompetence was assessed with the patient

standing with the weight off the limb being tested. Thecalf was squeezed and released by hand while an area ofinterest was being insonnated using colour and thenspectral Doppler. Reversed flow of over 1 s duration wasclassed as abnormal, but only regarded as significant if itpersisted longer than the initial augmentation of venousflow from the calf squeeze. The presence of reflux in thefemoral and popliteal veins, the long and short saphenousveins and at the saphenofemoral and saphenopoplitealjunctions was assessed routinely. The examination wasextended to search for incompetent thigh perforators andto ensure that the source of reflux to any visible varicositieswas traced.The sensitivity, specificity, positive predictive value

and negative predictive values of hand-held Dopplerassessment compared with the 'gold standard', duplexscanning, were calculated (18,19).

Results

Using the CEAP classification of chronic venousinsufficiency (20), the clinical severity of the venousdisease in each limb is outlined in Table I. The aetiologyof the venous disease was primary in all cases.The anatomical distribution of sites of reflux is outlined

in Table II. There were no limbs with obstructive diseaseor evidence of previous deep venous thrombosis. Thepathophysiology of the venous disease was reflux in 97limbs; no sites of deep to superficial reflux were found in11 limbs, although there was reflux detected in thesuperficial varicosities in 10 of these 11 limbs. Theremaining one study limb had telangectasia.The superficial femoral vein and the popliteal vein were

assessed as being patent in 108 limbs (100%) examined

Table I. Clinical presentation of 108 limbs assessed withprimary varicose veins

Number ofCEAP class Clinical signs limbs

Class 0 No visible or palpablesigns of venous disease 0

Class 1 Telangectases, reticularveins, malleolar flare 1

Class 2 Varicose veins 96Class 3 Oedema without skin

changes 0Class 4 Skin changes ascribed to

venous disease (egpigmentation, venouseczema,lipodermatosclerosis 9

Class 5 Skin changes as definedabove with healedulceration 0

Class 6 Skin changes as definedabove with activeulceration 2

390 P Jf Kent and M Weston

using HHD and confirmed on duplex scanning in allcases. It is interesting to note that deep venous reflux waspresent on duplex scanning in the superficial femoral vein,the popliteal vein, or both, in 15% of limbs in this studyof patients with primary varicose veins (Table II).The sensitivity of a test is the proportion of true-

positives that are correctly identified by the test. Thespecificity is the proportion of true-negatives that are

correctly diagnosed by the test (18). The positivepredictive value is the proportion of patients withpositive test results who are correctly diagnosed. Thenegative predictive value is the proportion of patients withnegative test results who are correctly diagnosed (19).These values are outlined in Table III. The sensitivity,specificity, positive predictive value and negative pre-dictive value of HHD testing with the application of a

tourniquet to determine the presence of reflux in the SFV,PV, and the presence of mid-thigh perforator incompe-tence are also outlined in Table III.

If operations planned on the basis of HHD are

compared with those planned on the basis of duplexscanning, it can be seen that the appropriate surgicalprocedure is performed on 75 limbs (70%). However,more extensive surgery than is necessary would beperformed on 25 limbs (23%) and inadequate surgery

performed on seven limbs (7%) (Table IV). One limbwould require microinjection sclerotherapy or laser

therapy for telangectasia and is not represented in TableIV or Table V.

It is apparent from Table IV that there would be a

significant number of inappropriate procedures performedon the saphenopopliteal junction; also, 3/8 (37%) patientswith no apparent deep to superficial reflux on hand-heldDoppler assessment would require more extensive surgery

than that suggested on the basis of HHD.Therefore, if a policy of requesting a duplex scan on all

limbs with (i) suspected SPJ reflux (n = 33), (ii) no

identifiable site of reflux (n = 8), or (iii) suspectedposterior thigh perforator reflux (n =1) on HHD hadbeen used, the operations planned using this policy wouldhave been as outlined in Table V. Using this selectiveapproach, duplex scanning would be required in only39% of limbs assessed. It can be seen that the appropriatesurgical procedure would be performed in 101 (94%)limbs, that unnecessary saphenofemoral junction ligationwould be performed in 5 (5%) limbs and that inadequatesurgery would be performed in only 1 (1%) limb.

Discussion

Hand-held Doppler assessment of patients with varicoseveins is an investigation which is quick, easy to perform inthe outpatient department and requires minimal equip-

Table II. Anatomical sites of venous reflux identified using colour duplex scanning in 108 limbs with primary varicoseveins

No deep vein SFV reflux PV reflux SFV & PVSite reflux only only reflux

SFJ reflux 3 _SFJ & LSV reflux 57 1 3 1SFJ & LSV & SPJ 3 1 2 1SFJ & LSV & MTP 3 _ _ _LSV & MTP & SPJ 1 -

MTP 2 - -

MTP & LSV 5 - 2 1MTP & SPJ 1 - -

LSV 2 - -

SPJ 4 _ 4None 11

Table III. Sensitivity, specificity, positive predictive value and negative predictive value of hand-held Dopplerexamination in conjunction with tourniquet testing in patients with primary varicose veins

Positive NegativeSite examined Sensitivity Specificity predictive value predictive value

SFJ reflux 0.93 0.91 0.96 0.85SFV reflux 0.60 0.48 0.06 0.96LSV reflux 0.95 0.68 0.91 0.80MTP reflux 0.87 0.26 0.16 0.92SPJ reflux 0.82 0.80 0.43 0.96PV reflux 0.50 0.90 0.44 0.92

Duplex scanning of varicose veins 391

Table IV. Operations proposed on each limb on the basis of HHD compared with duplexMSA SF7 P F &SJT TP & SP'

---- ---------

Shade ara2r*rcdrswihaepooe ybt netgtos toelwradt h etaeecsieadtoeupradtthe right are inadequate~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~------------

*Inadquat and 16aprprat

Table V. Operations proposed on each limb on the basis of HHD and selective duplex scanning compared with duplexscanning all patients

MSA SF3 SP SF7 & SPf Ti' TP & SP'

--------------

SFJ&SPJ

TP&SP - --

Shaded areas are procedures which are proposed by both investigations, those lower and to the left are excessive and those upper and tothe right are inadequate

ment. Some expertise is needed to perform theexamination, although this may easily be acquired (21).The accuracy of HHD assessment of varicose veins has

been documented previously (4,5,7,8,22-24). The con-clusions of these studies differ significantly with respect tothe reported accuracy ofHHD. A number of factors need tobe considered when interpreting the results ofthese studiesas different clinical methodologies were used. Dopplerprobe frequency varied from 4 MHz to 9.4 MHfz. In somestudies the patient was examined in the supine position andreflux precipitated by a Valsalva manoeuvre, while in othersthe patient was standing with assessment of refiux afterrelease of calf squeeze. The HHD studies were performedby a variety of individuals, including technicians, traineesurgeons and trained surgeons. Comparison of HHDfindings was with operative findings in earlier studies andwith duplex findings in the later studies. In the formerstudies, assessment ofnegative Doppler findings in patientswith varicose veins was not examined, making it impossibleto determine the true accuracy ofHHD assessment. In onlytwo studies wasHHD and duplex assessment performed onthe same day, raising the possibility of the development ofnew sites of reflux between the examinations in the otherstudies. The study populations were heterogeneous innearly all cases, including patients with recurrent varicoseveins. All of these factors need to be taken into considera-tion when evaluating the accuracy of HHD assessment ofvaricose veins.

In patients with primary previously untreated varicoseveins, the results presented in this paper confirm that

HHD is a reliable test when compared with duplexscanning in assessing SFJ and LSV reflux.The results also confirm the observation that assess-

ment of SPJ reflux using HHD is not good, with a lowpositive predictive value, although the high negativepredictive value suggests that absence of SPJ reflux isaccurately assessed. There are a number of reasons for thepoor positive predictive value. The anatomy of the SPJ isvariable and therefore exact localisation using clinical orHHD methods is inaccurate (7,16,25,26). The presenceof varicosities in the popliteal fossa may also give amistaken impression of SPJ reflux as these may fill fromthe long saphenous system via the medial superficial thighbranch of the long saphenous vein.The addition of tourniquet testing to HHD assessment

is inaccurate and unhelpful in the assessment of deepvenous refiux and mid-thigh perforator reflux because ofthe poor positive predictive values obtained using thismodification. This is probably owing to inadequatecompression of the superficial veins by the tourniquet(27). The clinical importance of accurately assessingreflux in the superficial femoral and popliteal vein isdebatable as there is evidence that deep venous refiux maybe abolished by surgical treatment of superficial venousincompetence (28). Surgical technique may also modifythe clinical importance of identification of MTP refluxassociated with LSV refiux, as stripping of the longsaphenous vein to knee level may prevent recurrentvaricose veins originating from mid-thigh perforatorreflux (29).

392 P J Kent and M J Weston

If we plan therapeutic procedures on the basis of theHHD alone, 70% of limbs will have adequate andappropriate treatment and 23% of limbs will have aprocedure which is excessive (ligation of SFJ or SPJ),although they will also have the appropriate procedureperformed. Only 7% of limbs will have an inadequateprocedure resulting in possible recurrence of the varicoseveins.Duplex imaging is time-consuming (examination takes

10 min for one leg, 15 min for both-MJW) and costlyboth in terms of the capital cost of the machine and inpersonnel salary costs. Accuracy of the results usingduplex depends on the experience of the operator.Invariably, where duplex is performed a waiting listdevelops because of the volume of the workload. It is alsoapparent that duplex should be performed as close to thetime of surgery as possible if its benefits are to bemaximised (17). These factors must be weighed againstthe accuracy of the information gained. There is sufficientevidence to suggest that routine duplex examination ofpatients with recurrent varicose veins is worthwhile(30,31).

If a policy of selective duplex scanning of patientsfound to have suspected SPJ reflux, no identifiable site ofreflux, or suspected posterior thigh perforator reflux onHHD is applied, this will reduce the number ofunnecessary procedures to 5%, and only 1% of limbswould have an inadequate procedure, potentially resultingin recurrence. This would require duplex scanning of39% of limbs presenting with primary, previouslyuntreated varicose veins. This may not indicate anincreased workload as patients with suspected sapheno-popliteal reflux (31% of limbs) on HHD would probablyhave the diagnosis confirmed at the time of preoperativelocalisation and marking of the SPJ using duplex scanningor venography (25,26).

In conclusion, we believe that HHD is an inexpensive,easy to perform clinical test which can be carried out inthe outpatient department. If only patients with suspectedSPJ reflux, posterior thigh reflux or no detectable sourceof reflux are referred for duplex scanning it would reducethe workload of the vascular laboratory without compro-mising the quality of patient care.

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Received 27 May 1998