- Email: [email protected]
Surgical Reconstruction without Preoperative Angiography in Patients with Aortoiliac Occlusive Disease
Surgical Reconstruction without Preoperative Angiography in Patients with Aortoiliac Occlusive Disease Annika BostroÈm Ardin, MD, PhD, Sadettin Karacagil, MD, PhD, Anders Hellberg, MD, PhD, Christer Ljungman, MD, PhD, Karl Logason, MD, PhD, and GoÈrel OÈstholm, RN, Uppsala, Sweden
The objective of this study was to evaluate the feasibility of performing surgical reconstructions in patients with aortoiliac occlusive disease with ®ndings obtained solely from duplex scanning. Between January 1995 through December 1999, among 112 patients who underwent surgical intervention due to aortoiliac occlusive disease, 44 were operated on with ®ndings obtained solely from preoperative duplex scanning. Deviations from preoperatively planned surgical interventions according to duplex scan ®ndings and the outcome were analyzed. Our results showed that surgical reconstructions for treatment of aortoiliac occlusive disease can be safely performed by using duplex scanning as the sole preoperative diagnostic modality in patients with conclusive duplex scan ®ndings.
INTRODUCTION Duplex scanning has been shown in previous studies, to be an accurate method of diagnostic imaging modality for assessment of lower limb arterial disease.1-5 Conversely, other investigators have reported a less satisfactory correlation with conventional angiography in the evaluation of aortoiliac occlusive disease.6-8 Apart from patientrelated factors, the contradictory results, might also be explained by the operator, method, or equipment-dependent nature of duplex scanning. The ultimate aim of noninvasive investigation of patients with arterial occlusive disease in the aortoiliac segment is the selection of an endovascular or Department of Surgery, University Hospital, Uppsala, Sweden. Correspondence to: A. BostroÈm Ardin, MD, Department of Surgery, University Hospital, Uppsala, 751 85, Sweden, E-mail: annika.bostrom @kiurgi.uu.se Ann Vasc Surg 2002; 16: 273-278 DOI: 10.1007/s10016-001-0237-y Ó Annals of Vascular Surgery Inc. Published online: 20 May 2002
1 surgical intervention without having to obtain additional information, from contrast angiography. Despite wide application of duplex scanning, there are few publications on its use as the sole preoperative investigative tool prior to surgical reconstruction for treatment of aortoiliac occlusive disease. The aim of the present retrospective study was to report our experience with performing surgical reconstructions in patients with aortoiliac occlusive disease without preoperative angiography.
PATIENTS AND METHODS Between January 1995 through December 1999, the records of patients undergoing lower extremity arterial duplex scanning showing aortoiliac occlusive disease or inconclusive ®ndings were retrospectively analyzed to study the feasibility and results of surgical reconstructions performed without preoperative angiography. Among 112 patients who underwent surgical intervention due to aortoiliac occlusive disease, 44 were operated on with ®ndings obtained solely from preoperative duplex 273
274 BostroÈm Ardin et al.
scanning; this group constituted the basis of the present study. Twenty-six patients were men and 18 were women. The median age was 68 (range, 49-88). Nine (21%) had diabetes mellitus, 15 (34%) had coronary artery disease, 20 (45%) had hypertension, and 21 (48%) were smokers. The indications for surgery were disabling claudication in 18 patients, rest pain in 16, and ulcer/gangrene in 10. Twelve patients (27%) had critical lower limb ischemia (CLI) according to SVS/ICSVS reporting standards while 14 patients with rest pain or ulcer (32%) had either falsely elevated ankle pressures or had anklebrachial pressure index (ABPI) <0.5 and ankle pressure over 40 mmHg.9 The latter group was considered to have subcritical ischemia. Among eight patients with previous proximal reconstruction, one had occluded aortobifemoral bypass, seven had unilateral aortobifemoral graft limb occlusion, and one patient had occluded iliofemoral bypass. The median interval between the initial graft insertion and the secondary procedure was 16 (range, 8-52) months. The initial decision of whether to perform intervention was based on history, clinical investigation, and ankle pressure measurements. Potential candidates for intervention underwent duplex scanning. There were no strict guidelines for selection of patients for endovascular or surgical intervention but limbs having stenotic lesions <10 cm in length and occlusions <5 cm in length (categories 1, 2, and 3) in the iliac arteries according to duplex scan ®ndings were interpreted as being suitable for endovascular intervention.10 Stenotic lesions >10 cm in length, occlusions longer than 5 cm, or extensive bilateral disease (category 4) was considered unsuitable for endovascular intervention. Surgical intervention without preoperative angiography was performed only when duplex scan ®ndings were conclusive, providing suf®cient information on the status of in¯ow and runoff arteries and con®rming that the lesions were not suitable for percutaneous transluminal angioplasty (PTA) 2 according to the guidelines mentioned above. Duplex scanning was performed using an Acuson 128 XP or Sequoia ®tted with 2-6 MHz linear, 2-4 MHz convex or curved array probes (Mountainview, CA). Patients were not asked to fast prior to investigation. Imaging was performed from the infrarenal aorta to the distal popliteal arteries on both sides with the patient lying supine. Curved array or vector probes for abdominal and linear probes for peripheral investigations were used. The arteries were scanned on longitudinal and sometimes on cross section with color ¯ow imaging. Each arterial segment was examined along its en-
Annals of Vascular Surgery
tire length for color changes suggesting the presence of an arterial lesion. Peak systolic velocities (PSV) from these areas were compared with those of the normal segments immediately proximal and rarely distal to the lesions. Spectral Doppler waveforms were routinely obtained from common iliac, external iliac, common femoral, deep and super®cial femoral, and popliteal arteries at proximal, mid-, and distal segments of each artery, even in the absence of color changes. The spectral Doppler criteria used to classify stenoses were based on PSV ratio outlined by Legemate et al.1 A lesion with a PSV ratio >2.5 was considered hemodynamically signi®cant when the Doppler angle was £60°. If the arterial segment was clearly visualized with Bmode images but gave no detectable Doppler signals, it was considered occluded. The duplex scan ®ndings, including the type and length of lesions, were drawn on a diagram. Black and white spectral Doppler prints, together with relevant B-mode and color ¯ow images, were saved for documentation. The internal iliac arteries were not routinely investigated. In some patients with unilateral symptoms, the distal super®cial and the popliteal arteries were not investigated on the asymptomatic side. Each patient undergoing surgery without preoperative angiography underwent a repeated duplex scan on the day before surgery. The investigations were interpreted as nondiagnostic if the artery in question could not be visualized by B-mode images or if pulsed Doppler samples could not be obtained with an angle of insonation <60°. Patients with clinical indication for intervention and nondiagnostic duplex scans were referred to conventional angiography. The results obtained from preoperative duplex scanning were correlated with the operative ®ndings. Life tables for primary, primary-assisted, and secondary patency rates at 12 months were constructed by the actuarial method according to SVS/ ICSVS reporting standards.9 Duplex scanning was used to verify patency at either discharge or 1 month in all patients. Patients were followed with clinical evaluation and ankle pressure measurements. In patients with clinical suspicion of graft occlusion or a diminished anklebrachial index of >0.15, duplex scanning was performed.
RESULTS The treatment options and further diagnostic evaluation with angiography are shown in Table I for patients with conclusive or inconclusive duplex scans. The reasons for nondiagnostic duplex scans (23/310, 7.4%) were obesity or bowel gases ob-
Vol. 16, No. 3, 2002
Duplex scanning in aortoiliac occlusive disease 275
Table I. Treatment options and diagnostic evaluation with angiography for patients with conclusive or inconclusive duplex scan
Treatment
Patients with inconclusive Patients with conclusive scan scans (n) (n)
Conservative 77 Primary amputation 3 Surgery 44 Angiography Conservative 12 Amputation 4 PTA 85 Surgery 62 Total 287 (92.6%)
8 0 0 3 1 5 6 23 (7.4%)
structing the images in 14 patients or dif®culties in obtaining a Doppler angle of insonation <60° in 9 cases with tortuous vessels. Calci®cation was not a major limitation for imaging. In 85 patients with aortoiliac occlusive lesions, no further invasive diagnostic or interventional procedures were performed because of extensive iliac artery lesions in claudicants in whom surgical intervention was not indicated (n = 67), and (b) lesions suitable for PTA whose severity of symptoms did not justify intervention (n = l8). Fifteen patients with aortoiliac occlusive disease were treated conservatively following diagnostic angiography. The reasons for angiography in these patients were inconclusive duplex scan ®ndings in 3 and possible use of PTA in 12. The lesions were not suitable for PTA in six of these patients according to angiography. In the remaining six patients with suitable multiple lesions for PTA, conservative treatment was selected for various 4 reasons. Iliac artery PTA or PTA + stent were performed in 93 patients. Duplex scanning correctly selected 85 of these cases for endovascular intervention. Sixty-eight patients underwent surgical intervention following angiography. In 12 of these patients, duplex scan ®ndings wrongly suggested the possible use of endovascular intervention (n = 6; 9%) or were inconclusive (n = 6; 9%). In the remaining 56 (82%) patients undergoing surgery, retrospective analysis revealed that the surgical interventions could have been performed without preoperative angiography. The reason for performing diagnostic angiography prior to surgical intervention in patients with diagnostic duplex scan ®ndings was mainly due to policy differences among vascular surgeons.
The results of duplex scanning of aortoiliac arteries in patients undergoing surgery on the basis of duplex scan ®ndings are summarized in Table II. Nine patients had aneurysmal disease of the aorta and/or iliac artery in addition to occlusive lesions of the iliac arteries. Twenty patients had concomitant uni- (n = 9) or bilateral (n = 11) signi®cant stenoses (>50% diameter reduction) or occlusion of the femoropopliteal arteries. Two patients with CLI underwent concomittant infrainguinal bypass grafting. Seventeen aortobifemoral/iliacal, 6 iliofemoral, 19 femorofemoral, and 2 axillobifemoral bypasses were performed without preoperative angiography, which constituted 39% of all proximal arterial reconstructions (Table III). The number of total proximal arterial reconstructions performed for treatment of chronic occlusive disease gradually decreased during the study period. Among those patients undergoing aortobifemoral/iliac bypass grafting, there were no deviations from preoperatively planned surgical reconstructions according to duplex scan ®ndings. Technical details of the interventions in limbs undergoing iliofemoral and femorofemoral grafting regarding the site of proximal and distal anastomoses based on duplex scanning were also in agreement with operative ®ndings in all but one 5 patient. In this patient, the atherosclerotic changes in the external iliac artery were underestimated and the patient underwent femorofemoral bypass instead of initially planned endarterectomy in the common femoral artery. In two patients undergoing axillobifemoral bypass grafting, the sites of distal anastomoses were correctly selected by duplex scanning. Postoperative 30-day mortality following surgery performed without angiography was 2.2% (1/44). The cumulative primary life-table patency rate was 80% at 12 months in patients undergoing surgery without preoperative angiography (Table III). The primary-assisted and secondary patency rates at 12 months were 86% and 90%, respectively. In two patients graft occlusion was observed within 3 days after surgery. In one case with iliofemoral and femorofemoral bypass, the distal part of the iliofemoral graft was occluded but the femorofemoral graft was patent. The other patient had a femorofemoral bypass. The cause of graft occlusion in both cases was due to technical problems at the anastomotic sites. Thrombectomy and revision of the anastomoses resulted in patency for 4 and 10 months, respectively. Graft occlusion occurred in three patients between 1 and 12 months. One of these patients with multilevel disease underwent amputation following occlusion of femorofemoral
276 BostroÈm Ardin et al.
Annals of Vascular Surgery
Table II. Status of native arteries according to preoperative duplex scan ®ndings in patients undergoing surgery without preoperative angiography
Arterial segment
Segments with normal or <50% stenosis (n)
Segments with >50% stenosis or occlusion (n)
Segments with associated aneurysm (n)
Aorta Common iliac External iliac Common femoral
32 50 41 72
5 24 39 11
7 4 0 2a
a
False aneurysm in limbs with previously inserted aortobifemoral bypass.
Table III. Cumulative life-table analysis for primary patency rate in patients undergoing surgery without preoperative angiography (44 procedures) Withdrawn
Interval (months)
Grafts at risk (n)
Failed reconstructions (n)
Losta (n)
Died (n)
Interval patency
Cumulative patency SE (%) (%)
0-3 3-6 6-9 9-12
44 31 29 27
3 1 2 1
7 0 0 0
3 1 0 0
0.92 0.96 0.93 0.96
100 92 89 83
a
0 4.2 5 6.8
Number of patients withdrawn because of short time period since operation or loss to follow-up.
graft at 7 months and infrainguinal bypass grafting was not technically feasible. The other two patients with femorofemoral graft occlusion at 2 and 9 months underwent successful graft thrombectomy and infrainguinal bypass grafting. In one patient with CLI, duplex scanning demonstrated a signi®cant stenosis in the donor iliac artery of a femorofemoral bypass at 2 months. This patient underwent femoropopliteal bypass and intraoperative PTA of the donor side with successful outcome. In one patient with femorofemoral bypass graft occlusion at 4 months, resulting in claudication, no further intervention was performed. The cumulative primary patency rate at 12 months following 68 surgical interventions in patients with preoperative angiography was 83%, and the primary-assisted and secondary patency rates were 83% and 91%, respectively. There was no signi®cant difference in patency rates between patients undergoing surgery with or without preoperative angiography.
DISCUSSION Conventional contrast angiography together with intraarterial pressure measurements is generally considered the gold standard for grading aortoiliac occlusive lesions and provides the necessary ana-
tomic information for selection of patients for endovascular or surgical intervention. However, angiography is invasive and has a low but wellknown risk of complications, related to both the procedure and to the renal toxicity of the contrast medium. Noninvasive diagnosis of lower limb arterial disease with duplex scanning has emerged as an alternative to conventional angiography. Recent developments in ultrasound technology have raised the possibility of performing surgical reconstructions in patients with lower limb arterial occlusive disease without the need for conventional angiography.5,11-14 Improvements in B-mode, color ¯ow imaging and probe technology have signi®cantly contributed to reliable evaluation of intraabdominal arteries. However, one has to be aware of the inherent limitations of duplex scanning, such as dif®culties in obtaining satisfactory images or Doppler analysis in some patients, due either to obesity, bowel gas, or extensive calci®cation in the arterial wall. It should be noted that the most important limitation is probably the experience of the operator. In the present study, all the investigations were performed by experienced vascular technologists or vascular surgeons. Another disadvantage of duplex scanning is the lack of visual display of the vascular anatomy, as with angiography. This is probably one of the reasons for performing diag-
Vol. 16, No. 3, 2002
nostic angiography prior to surgical intervention in patients with diagnostic duplex scan ®ndings and explains the policy differences among vascular surgeons. However, attitudes regarding the need for angiography in surgical candidates with conclusive duplex scan ®ndings are changing. It is likely that the number of diagnostic angiographies in these patients will be further reduced in the near future by continuous improvements in ultrasound technology and documentation techniques. The accuracy of duplex scanning in the evaluation of lower limb arteries has been extensively evaluated by comparing ®ndings with conventional angiography and/or intraarterial pressure measurements.1-5 Many authors have stated that duplex scanning is as good as if not better than angiography with respect to aortoiliac occlusive lesions when adequate images are obtained. It is therefore important to know when the information from duplex scanning is not conclusive. The frequency of nondiagnostic scans depends on the equipment and the experience of the operator, but is generally estimated to be around 5-10% in the aortoiliac segment.2-7 Better bowel preparation for elimination of bowel gases and recent innovations in echoenhancement might further increase the diagnostic power of ultrasound.15,16 The frequency of nondiagnostic aortotiliac duplex scanning in the present study was 7.4%. Our previous experience in a prospective study demonstrated a good correlation between duplex scanning and conventional angiography in the assessment of aortoiliac arteries. The accuracy of duplex scanning was 87% in diagnosing signi®cant stenosis or occlusion.3 Although duplex scanning has been reported to be as accurate as angiography in detecting hemodynamically signi®cant aortoiliac stenoses or occlusions, there are few publications on surgical interventions performed without preoperative conventional angiography. Bodily et al.11 reported successful application of duplex scanning in 11 patients undergoing aortoiliac reconstructions without angiography. Van der Zaag et al.12 performed 22 aortoiliac reconstructive surgeries without angiography and in only two patients were deviations from the preoperatively planned procedure observed. Duplex scanning provided satisfactory preoperative information in 27 patients undergoing iliac reconstructions in a study by Sarkar et al.13 The results of this study demonstrate that surgical reconstructions due to atherosclerotic occlusive disease of the aortoiliac arteries is feasible on the basis of duplex scan alone. There were no unexpected operative ®ndings with regard to selection of anastomotic sites in all but 1 of 44 cases. It can be
Duplex scanning in aortoiliac occlusive disease 277
argued that operative ®ndings are not totally reliable and the ®ndings were not con®rmed by intraoperative angiography. However, the results were similar in patients undergoing surgery with or without preoperative angiography and early duplex scan surveillance did not show any ®ndings implicating wrong selection of in¯ow or recipient arteries. It can also be argued that some of those patients who underwent surgery without preoperative angiography could have been treated by PTA. During recent years, endovascular treatment of aortoiliac occlusive lesions has been widely used in patients with extensive lesions and the number of surgical interventions, especially aortobifemoral bypass grafting, have diminished in many centers. This is an important issue with respect to de®nition of lesions suitable for surgical intervention, and affects the number of reconstructions performed without preoperative angiography. In conclusion, duplex scanning provides valuable information for therapeutic decision making in patients with aortoiliac occlusive disease. Surgical reconstructions without preoperative angiography can be safely performed in patients with satisfactory visualization of the entire aortoiliac and femoropopliteal segments through duplex scanning. The frequency with which it can be applied depends on the criteria used in selection of cases for endovascular intervention and on the experience of the vascular laboratory. Funding for this study was received from the Swedish Medical Research Council, grant no.00759, Swedish Heart and Lung Foundation. REFERENCES 1. Legemate DA, Teeuwen G, Hoeneveld H, Eikelboom BC. Value of duplex scanning compared with angiography and pressure measurements in the assessment of aortoiliac lesions. Br J Surg 1991;78:1003-1008. 2. Moneta GL, Yeager RA, Antonovic R, et al. Accuracy of lower extremity arterial duplex mapping. J Vasc Surg 1992;15:275-284. 3. Karacagil S, LoÈfberg AM, Almgren B, et al. Duplex ultrasound scanning for diagnosis of aortoiliac and femoropopliteal arterial disease. Vasa 1994;23:325-329. 4. Karacagil S, LoÈfberg AM, Granbo A, LoÈrelius LE, Bergqvist D. Value of duplex scanning in evaluation of crural and foot arteries in limbs with severe lower limb ischaemiaÐa prospective comparison with angiography. Eur J Vasc Endovasc Surg 1996;12:300-3003. 6 5. Schneider PA, Ogawa DY, Rush MP. Lower extremity revascularization without contrast arteriography: a prospective study of operation based upon duplex mapping. Cardiovasc Surg 1999;7:699-703. 6. Mulligan SA, Matsuda T, Lanzer P, et al. Peripheral arterial occlusive disease: prospective comparison of MR angiogra-
278 BostroÈm Ardin et al.
7.
8.
9.
10.
11.
12.
phy and color duplex US with conventional angiography. Radiology 1991;178:695-700. Rosfors S, Eriksson M, HoÈglund N, Johansson G. Duplex ultrasound in patients with suspected aorto-iliac occlusive disease. Eur J Vasc Surg 1993;7:513-517. Lai DT, Huber D, Glasson R, et al. Color-coded duplex ultrasonography in selection of patients for transluminal angioplasty. Australas Radiol 1995;39:243-245. Rutherford RB, Baker D, Ernst C, et al. Recommended standards for reports dealing with lower extremity ischaemia: revised version. J Vasc Surg 1997;26:517-538. Pentecost MJ, Criqui MH, Dorros G, et al. Guidelines for peripheral percutaenous transluminal angioplasty of the abdominal aorta and lower extremity vessels. Circulation 1994;89:511-531. Bodily K, Buttorff J, Nordesgaard A, Osborne R Jr. Aortoiliac reconstruction without angiography. Am J Surg 1996; 171:505-507. van der Zaag ES, Legemate DA, Nguyen T, Balm R, Jacobs MJ. Aortoiliac reconstructive surgery based upon the results
Annals of Vascular Surgery
13.
14.
15.
16.
7
of duplex scanning. Eur J Vasc Endovasc Surg 1998;16:383389. Sarkar R, Ro KM, Obrand DI, Ahn SS. Lower extremity vascular reconstruction and endovascular surgery without preoperative angiography. Am J Surg 1998;176:203207. Ascher E, Mazzariol F, Hingorani A, Salles-Cunha S, Gade P. The use of duplex ultrasound arterial mapping as an alternative to conventional arteriography for primary and secondary infrapopliteal bypasses. Am J Surg 1999;178:162165. Whiteley MS, Harris RA, Horrocks M. Aorto-iliac segment examination with colour ¯ow duplexÐa pilot study using Klean Prep, to improve the image quality. Eur J Vasc Endovasc Surg 1995;10:192-197. Vogt KC, Jensen F, Schroeder TV. Does Doppler signal enhancement with Levovist improve the diagnostic con®dence of duplex scanning of the iliac arteries? A pilot study with correlation to intravascular ultrasound. Eur J Ultrasound 1998;7:159-165.
The objective of this study was to evaluate the feasibility of performing surgical reconstructions in patients with aortoiliac occlusive disease with ®ndings obtained solely from duplex scanning. Between January 1995 through December 1999, among 112 patients who underwent surgical intervention due to aortoiliac occlusive disease, 44 were operated on with ®ndings obtained solely from preoperative duplex scanning. Deviations from preoperatively planned surgical interventions according to duplex scan ®ndings and the outcome were analyzed. Our results showed that surgical reconstructions for treatment of aortoiliac occlusive disease can be safely performed by using duplex scanning as the sole preoperative diagnostic modality in patients with conclusive duplex scan ®ndings.
INTRODUCTION Duplex scanning has been shown in previous studies, to be an accurate method of diagnostic imaging modality for assessment of lower limb arterial disease.1-5 Conversely, other investigators have reported a less satisfactory correlation with conventional angiography in the evaluation of aortoiliac occlusive disease.6-8 Apart from patientrelated factors, the contradictory results, might also be explained by the operator, method, or equipment-dependent nature of duplex scanning. The ultimate aim of noninvasive investigation of patients with arterial occlusive disease in the aortoiliac segment is the selection of an endovascular or Department of Surgery, University Hospital, Uppsala, Sweden. Correspondence to: A. BostroÈm Ardin, MD, Department of Surgery, University Hospital, Uppsala, 751 85, Sweden, E-mail: annika.bostrom @kiurgi.uu.se Ann Vasc Surg 2002; 16: 273-278 DOI: 10.1007/s10016-001-0237-y Ó Annals of Vascular Surgery Inc. Published online: 20 May 2002
1 surgical intervention without having to obtain additional information, from contrast angiography. Despite wide application of duplex scanning, there are few publications on its use as the sole preoperative investigative tool prior to surgical reconstruction for treatment of aortoiliac occlusive disease. The aim of the present retrospective study was to report our experience with performing surgical reconstructions in patients with aortoiliac occlusive disease without preoperative angiography.
PATIENTS AND METHODS Between January 1995 through December 1999, the records of patients undergoing lower extremity arterial duplex scanning showing aortoiliac occlusive disease or inconclusive ®ndings were retrospectively analyzed to study the feasibility and results of surgical reconstructions performed without preoperative angiography. Among 112 patients who underwent surgical intervention due to aortoiliac occlusive disease, 44 were operated on with ®ndings obtained solely from preoperative duplex 273
274 BostroÈm Ardin et al.
scanning; this group constituted the basis of the present study. Twenty-six patients were men and 18 were women. The median age was 68 (range, 49-88). Nine (21%) had diabetes mellitus, 15 (34%) had coronary artery disease, 20 (45%) had hypertension, and 21 (48%) were smokers. The indications for surgery were disabling claudication in 18 patients, rest pain in 16, and ulcer/gangrene in 10. Twelve patients (27%) had critical lower limb ischemia (CLI) according to SVS/ICSVS reporting standards while 14 patients with rest pain or ulcer (32%) had either falsely elevated ankle pressures or had anklebrachial pressure index (ABPI) <0.5 and ankle pressure over 40 mmHg.9 The latter group was considered to have subcritical ischemia. Among eight patients with previous proximal reconstruction, one had occluded aortobifemoral bypass, seven had unilateral aortobifemoral graft limb occlusion, and one patient had occluded iliofemoral bypass. The median interval between the initial graft insertion and the secondary procedure was 16 (range, 8-52) months. The initial decision of whether to perform intervention was based on history, clinical investigation, and ankle pressure measurements. Potential candidates for intervention underwent duplex scanning. There were no strict guidelines for selection of patients for endovascular or surgical intervention but limbs having stenotic lesions <10 cm in length and occlusions <5 cm in length (categories 1, 2, and 3) in the iliac arteries according to duplex scan ®ndings were interpreted as being suitable for endovascular intervention.10 Stenotic lesions >10 cm in length, occlusions longer than 5 cm, or extensive bilateral disease (category 4) was considered unsuitable for endovascular intervention. Surgical intervention without preoperative angiography was performed only when duplex scan ®ndings were conclusive, providing suf®cient information on the status of in¯ow and runoff arteries and con®rming that the lesions were not suitable for percutaneous transluminal angioplasty (PTA) 2 according to the guidelines mentioned above. Duplex scanning was performed using an Acuson 128 XP or Sequoia ®tted with 2-6 MHz linear, 2-4 MHz convex or curved array probes (Mountainview, CA). Patients were not asked to fast prior to investigation. Imaging was performed from the infrarenal aorta to the distal popliteal arteries on both sides with the patient lying supine. Curved array or vector probes for abdominal and linear probes for peripheral investigations were used. The arteries were scanned on longitudinal and sometimes on cross section with color ¯ow imaging. Each arterial segment was examined along its en-
Annals of Vascular Surgery
tire length for color changes suggesting the presence of an arterial lesion. Peak systolic velocities (PSV) from these areas were compared with those of the normal segments immediately proximal and rarely distal to the lesions. Spectral Doppler waveforms were routinely obtained from common iliac, external iliac, common femoral, deep and super®cial femoral, and popliteal arteries at proximal, mid-, and distal segments of each artery, even in the absence of color changes. The spectral Doppler criteria used to classify stenoses were based on PSV ratio outlined by Legemate et al.1 A lesion with a PSV ratio >2.5 was considered hemodynamically signi®cant when the Doppler angle was £60°. If the arterial segment was clearly visualized with Bmode images but gave no detectable Doppler signals, it was considered occluded. The duplex scan ®ndings, including the type and length of lesions, were drawn on a diagram. Black and white spectral Doppler prints, together with relevant B-mode and color ¯ow images, were saved for documentation. The internal iliac arteries were not routinely investigated. In some patients with unilateral symptoms, the distal super®cial and the popliteal arteries were not investigated on the asymptomatic side. Each patient undergoing surgery without preoperative angiography underwent a repeated duplex scan on the day before surgery. The investigations were interpreted as nondiagnostic if the artery in question could not be visualized by B-mode images or if pulsed Doppler samples could not be obtained with an angle of insonation <60°. Patients with clinical indication for intervention and nondiagnostic duplex scans were referred to conventional angiography. The results obtained from preoperative duplex scanning were correlated with the operative ®ndings. Life tables for primary, primary-assisted, and secondary patency rates at 12 months were constructed by the actuarial method according to SVS/ ICSVS reporting standards.9 Duplex scanning was used to verify patency at either discharge or 1 month in all patients. Patients were followed with clinical evaluation and ankle pressure measurements. In patients with clinical suspicion of graft occlusion or a diminished anklebrachial index of >0.15, duplex scanning was performed.
RESULTS The treatment options and further diagnostic evaluation with angiography are shown in Table I for patients with conclusive or inconclusive duplex scans. The reasons for nondiagnostic duplex scans (23/310, 7.4%) were obesity or bowel gases ob-
Vol. 16, No. 3, 2002
Duplex scanning in aortoiliac occlusive disease 275
Table I. Treatment options and diagnostic evaluation with angiography for patients with conclusive or inconclusive duplex scan
Treatment
Patients with inconclusive Patients with conclusive scan scans (n) (n)
Conservative 77 Primary amputation 3 Surgery 44 Angiography Conservative 12 Amputation 4 PTA 85 Surgery 62 Total 287 (92.6%)
8 0 0 3 1 5 6 23 (7.4%)
structing the images in 14 patients or dif®culties in obtaining a Doppler angle of insonation <60° in 9 cases with tortuous vessels. Calci®cation was not a major limitation for imaging. In 85 patients with aortoiliac occlusive lesions, no further invasive diagnostic or interventional procedures were performed because of extensive iliac artery lesions in claudicants in whom surgical intervention was not indicated (n = 67), and (b) lesions suitable for PTA whose severity of symptoms did not justify intervention (n = l8). Fifteen patients with aortoiliac occlusive disease were treated conservatively following diagnostic angiography. The reasons for angiography in these patients were inconclusive duplex scan ®ndings in 3 and possible use of PTA in 12. The lesions were not suitable for PTA in six of these patients according to angiography. In the remaining six patients with suitable multiple lesions for PTA, conservative treatment was selected for various 4 reasons. Iliac artery PTA or PTA + stent were performed in 93 patients. Duplex scanning correctly selected 85 of these cases for endovascular intervention. Sixty-eight patients underwent surgical intervention following angiography. In 12 of these patients, duplex scan ®ndings wrongly suggested the possible use of endovascular intervention (n = 6; 9%) or were inconclusive (n = 6; 9%). In the remaining 56 (82%) patients undergoing surgery, retrospective analysis revealed that the surgical interventions could have been performed without preoperative angiography. The reason for performing diagnostic angiography prior to surgical intervention in patients with diagnostic duplex scan ®ndings was mainly due to policy differences among vascular surgeons.
The results of duplex scanning of aortoiliac arteries in patients undergoing surgery on the basis of duplex scan ®ndings are summarized in Table II. Nine patients had aneurysmal disease of the aorta and/or iliac artery in addition to occlusive lesions of the iliac arteries. Twenty patients had concomitant uni- (n = 9) or bilateral (n = 11) signi®cant stenoses (>50% diameter reduction) or occlusion of the femoropopliteal arteries. Two patients with CLI underwent concomittant infrainguinal bypass grafting. Seventeen aortobifemoral/iliacal, 6 iliofemoral, 19 femorofemoral, and 2 axillobifemoral bypasses were performed without preoperative angiography, which constituted 39% of all proximal arterial reconstructions (Table III). The number of total proximal arterial reconstructions performed for treatment of chronic occlusive disease gradually decreased during the study period. Among those patients undergoing aortobifemoral/iliac bypass grafting, there were no deviations from preoperatively planned surgical reconstructions according to duplex scan ®ndings. Technical details of the interventions in limbs undergoing iliofemoral and femorofemoral grafting regarding the site of proximal and distal anastomoses based on duplex scanning were also in agreement with operative ®ndings in all but one 5 patient. In this patient, the atherosclerotic changes in the external iliac artery were underestimated and the patient underwent femorofemoral bypass instead of initially planned endarterectomy in the common femoral artery. In two patients undergoing axillobifemoral bypass grafting, the sites of distal anastomoses were correctly selected by duplex scanning. Postoperative 30-day mortality following surgery performed without angiography was 2.2% (1/44). The cumulative primary life-table patency rate was 80% at 12 months in patients undergoing surgery without preoperative angiography (Table III). The primary-assisted and secondary patency rates at 12 months were 86% and 90%, respectively. In two patients graft occlusion was observed within 3 days after surgery. In one case with iliofemoral and femorofemoral bypass, the distal part of the iliofemoral graft was occluded but the femorofemoral graft was patent. The other patient had a femorofemoral bypass. The cause of graft occlusion in both cases was due to technical problems at the anastomotic sites. Thrombectomy and revision of the anastomoses resulted in patency for 4 and 10 months, respectively. Graft occlusion occurred in three patients between 1 and 12 months. One of these patients with multilevel disease underwent amputation following occlusion of femorofemoral
276 BostroÈm Ardin et al.
Annals of Vascular Surgery
Table II. Status of native arteries according to preoperative duplex scan ®ndings in patients undergoing surgery without preoperative angiography
Arterial segment
Segments with normal or <50% stenosis (n)
Segments with >50% stenosis or occlusion (n)
Segments with associated aneurysm (n)
Aorta Common iliac External iliac Common femoral
32 50 41 72
5 24 39 11
7 4 0 2a
a
False aneurysm in limbs with previously inserted aortobifemoral bypass.
Table III. Cumulative life-table analysis for primary patency rate in patients undergoing surgery without preoperative angiography (44 procedures) Withdrawn
Interval (months)
Grafts at risk (n)
Failed reconstructions (n)
Losta (n)
Died (n)
Interval patency
Cumulative patency SE (%) (%)
0-3 3-6 6-9 9-12
44 31 29 27
3 1 2 1
7 0 0 0
3 1 0 0
0.92 0.96 0.93 0.96
100 92 89 83
a
0 4.2 5 6.8
Number of patients withdrawn because of short time period since operation or loss to follow-up.
graft at 7 months and infrainguinal bypass grafting was not technically feasible. The other two patients with femorofemoral graft occlusion at 2 and 9 months underwent successful graft thrombectomy and infrainguinal bypass grafting. In one patient with CLI, duplex scanning demonstrated a signi®cant stenosis in the donor iliac artery of a femorofemoral bypass at 2 months. This patient underwent femoropopliteal bypass and intraoperative PTA of the donor side with successful outcome. In one patient with femorofemoral bypass graft occlusion at 4 months, resulting in claudication, no further intervention was performed. The cumulative primary patency rate at 12 months following 68 surgical interventions in patients with preoperative angiography was 83%, and the primary-assisted and secondary patency rates were 83% and 91%, respectively. There was no signi®cant difference in patency rates between patients undergoing surgery with or without preoperative angiography.
DISCUSSION Conventional contrast angiography together with intraarterial pressure measurements is generally considered the gold standard for grading aortoiliac occlusive lesions and provides the necessary ana-
tomic information for selection of patients for endovascular or surgical intervention. However, angiography is invasive and has a low but wellknown risk of complications, related to both the procedure and to the renal toxicity of the contrast medium. Noninvasive diagnosis of lower limb arterial disease with duplex scanning has emerged as an alternative to conventional angiography. Recent developments in ultrasound technology have raised the possibility of performing surgical reconstructions in patients with lower limb arterial occlusive disease without the need for conventional angiography.5,11-14 Improvements in B-mode, color ¯ow imaging and probe technology have signi®cantly contributed to reliable evaluation of intraabdominal arteries. However, one has to be aware of the inherent limitations of duplex scanning, such as dif®culties in obtaining satisfactory images or Doppler analysis in some patients, due either to obesity, bowel gas, or extensive calci®cation in the arterial wall. It should be noted that the most important limitation is probably the experience of the operator. In the present study, all the investigations were performed by experienced vascular technologists or vascular surgeons. Another disadvantage of duplex scanning is the lack of visual display of the vascular anatomy, as with angiography. This is probably one of the reasons for performing diag-
Vol. 16, No. 3, 2002
nostic angiography prior to surgical intervention in patients with diagnostic duplex scan ®ndings and explains the policy differences among vascular surgeons. However, attitudes regarding the need for angiography in surgical candidates with conclusive duplex scan ®ndings are changing. It is likely that the number of diagnostic angiographies in these patients will be further reduced in the near future by continuous improvements in ultrasound technology and documentation techniques. The accuracy of duplex scanning in the evaluation of lower limb arteries has been extensively evaluated by comparing ®ndings with conventional angiography and/or intraarterial pressure measurements.1-5 Many authors have stated that duplex scanning is as good as if not better than angiography with respect to aortoiliac occlusive lesions when adequate images are obtained. It is therefore important to know when the information from duplex scanning is not conclusive. The frequency of nondiagnostic scans depends on the equipment and the experience of the operator, but is generally estimated to be around 5-10% in the aortoiliac segment.2-7 Better bowel preparation for elimination of bowel gases and recent innovations in echoenhancement might further increase the diagnostic power of ultrasound.15,16 The frequency of nondiagnostic aortotiliac duplex scanning in the present study was 7.4%. Our previous experience in a prospective study demonstrated a good correlation between duplex scanning and conventional angiography in the assessment of aortoiliac arteries. The accuracy of duplex scanning was 87% in diagnosing signi®cant stenosis or occlusion.3 Although duplex scanning has been reported to be as accurate as angiography in detecting hemodynamically signi®cant aortoiliac stenoses or occlusions, there are few publications on surgical interventions performed without preoperative conventional angiography. Bodily et al.11 reported successful application of duplex scanning in 11 patients undergoing aortoiliac reconstructions without angiography. Van der Zaag et al.12 performed 22 aortoiliac reconstructive surgeries without angiography and in only two patients were deviations from the preoperatively planned procedure observed. Duplex scanning provided satisfactory preoperative information in 27 patients undergoing iliac reconstructions in a study by Sarkar et al.13 The results of this study demonstrate that surgical reconstructions due to atherosclerotic occlusive disease of the aortoiliac arteries is feasible on the basis of duplex scan alone. There were no unexpected operative ®ndings with regard to selection of anastomotic sites in all but 1 of 44 cases. It can be
Duplex scanning in aortoiliac occlusive disease 277
argued that operative ®ndings are not totally reliable and the ®ndings were not con®rmed by intraoperative angiography. However, the results were similar in patients undergoing surgery with or without preoperative angiography and early duplex scan surveillance did not show any ®ndings implicating wrong selection of in¯ow or recipient arteries. It can also be argued that some of those patients who underwent surgery without preoperative angiography could have been treated by PTA. During recent years, endovascular treatment of aortoiliac occlusive lesions has been widely used in patients with extensive lesions and the number of surgical interventions, especially aortobifemoral bypass grafting, have diminished in many centers. This is an important issue with respect to de®nition of lesions suitable for surgical intervention, and affects the number of reconstructions performed without preoperative angiography. In conclusion, duplex scanning provides valuable information for therapeutic decision making in patients with aortoiliac occlusive disease. Surgical reconstructions without preoperative angiography can be safely performed in patients with satisfactory visualization of the entire aortoiliac and femoropopliteal segments through duplex scanning. The frequency with which it can be applied depends on the criteria used in selection of cases for endovascular intervention and on the experience of the vascular laboratory. Funding for this study was received from the Swedish Medical Research Council, grant no.00759, Swedish Heart and Lung Foundation. REFERENCES 1. Legemate DA, Teeuwen G, Hoeneveld H, Eikelboom BC. Value of duplex scanning compared with angiography and pressure measurements in the assessment of aortoiliac lesions. Br J Surg 1991;78:1003-1008. 2. Moneta GL, Yeager RA, Antonovic R, et al. Accuracy of lower extremity arterial duplex mapping. J Vasc Surg 1992;15:275-284. 3. Karacagil S, LoÈfberg AM, Almgren B, et al. Duplex ultrasound scanning for diagnosis of aortoiliac and femoropopliteal arterial disease. Vasa 1994;23:325-329. 4. Karacagil S, LoÈfberg AM, Granbo A, LoÈrelius LE, Bergqvist D. Value of duplex scanning in evaluation of crural and foot arteries in limbs with severe lower limb ischaemiaÐa prospective comparison with angiography. Eur J Vasc Endovasc Surg 1996;12:300-3003. 6 5. Schneider PA, Ogawa DY, Rush MP. Lower extremity revascularization without contrast arteriography: a prospective study of operation based upon duplex mapping. Cardiovasc Surg 1999;7:699-703. 6. Mulligan SA, Matsuda T, Lanzer P, et al. Peripheral arterial occlusive disease: prospective comparison of MR angiogra-
278 BostroÈm Ardin et al.
7.
8.
9.
10.
11.
12.
phy and color duplex US with conventional angiography. Radiology 1991;178:695-700. Rosfors S, Eriksson M, HoÈglund N, Johansson G. Duplex ultrasound in patients with suspected aorto-iliac occlusive disease. Eur J Vasc Surg 1993;7:513-517. Lai DT, Huber D, Glasson R, et al. Color-coded duplex ultrasonography in selection of patients for transluminal angioplasty. Australas Radiol 1995;39:243-245. Rutherford RB, Baker D, Ernst C, et al. Recommended standards for reports dealing with lower extremity ischaemia: revised version. J Vasc Surg 1997;26:517-538. Pentecost MJ, Criqui MH, Dorros G, et al. Guidelines for peripheral percutaenous transluminal angioplasty of the abdominal aorta and lower extremity vessels. Circulation 1994;89:511-531. Bodily K, Buttorff J, Nordesgaard A, Osborne R Jr. Aortoiliac reconstruction without angiography. Am J Surg 1996; 171:505-507. van der Zaag ES, Legemate DA, Nguyen T, Balm R, Jacobs MJ. Aortoiliac reconstructive surgery based upon the results
Annals of Vascular Surgery
13.
14.
15.
16.
7
of duplex scanning. Eur J Vasc Endovasc Surg 1998;16:383389. Sarkar R, Ro KM, Obrand DI, Ahn SS. Lower extremity vascular reconstruction and endovascular surgery without preoperative angiography. Am J Surg 1998;176:203207. Ascher E, Mazzariol F, Hingorani A, Salles-Cunha S, Gade P. The use of duplex ultrasound arterial mapping as an alternative to conventional arteriography for primary and secondary infrapopliteal bypasses. Am J Surg 1999;178:162165. Whiteley MS, Harris RA, Horrocks M. Aorto-iliac segment examination with colour ¯ow duplexÐa pilot study using Klean Prep, to improve the image quality. Eur J Vasc Endovasc Surg 1995;10:192-197. Vogt KC, Jensen F, Schroeder TV. Does Doppler signal enhancement with Levovist improve the diagnostic con®dence of duplex scanning of the iliac arteries? A pilot study with correlation to intravascular ultrasound. Eur J Ultrasound 1998;7:159-165.