[Current and Future Role of Vascular Surgery Expertise for Visceral Surgeons - an Expert Survey]. / Aktueller und künftiger Stellenwert der gefäßchirurgischen Expertise für Viszeralchirurgen ­ eine Expertenbefragung.

BACKGROUND: Due to improved surgical techniques and safer perioperative management, there has been an increase in radical abdominal and oncological operations. Simultaneous vascular interventions are increasingly necessary - either after preoperative planning or after an intraoperative vascular emergency. It is unclear whether German visceral surgeons have the required vascular surgical skills. An assessment of the current and future status of vascular techniques within visceral surgery is therefore the issue of the present survey. METHODS: A questionnaire was sent to the chairs of visceral surgery of German university hospitals and to the directors of non-academic surgical departments in 2017. Thus, we sought to assess the current and future status of vascular surgery within abdominal and oncological operations. There were person-, hospital-, system-, and intervention-related questions to be answered. RESULTS: Compared to non-academic hospitals, significantly more vascular interventions were performed within abdominal surgery at university hospitals (p < 0.001), where generally more such expertise is available. Surgical support from vascular surgeons is present in a majority of both academic and non-academic institutions (72.8%). However, almost one third of respondents expressed a desire for more vascular surgery expertise at their departments. An optional rotation in vascular surgery exists predominantly at university hospitals (92.9 vs. 73.8%; p = 0.031). A slim majority of all surgical managers assumes that vascular surgery will play an increasing role in the future of visceral and oncological surgery (51.6%) and favours obligatory rotation for visceral surgery residents of at least six months (54.1%). Necessary skills to be taught include thrombectomy and embolectomy (95.6%), vascular suture (98.6%) and patch (89.1%) as well as vascular bypass surgery (45.5%). CONCLUSIONS: There is an expert consensus that vascular surgery is of increasing significance for visceral surgeons. In spite of the possibility of optional rotations for residents at most hospitals, there seems to be a demand for more expertise in vascular surgery at several departments. Obligatory rotation in vascular surgery should be discussed within training programs for visceral surgery.

[Vascular Complications and Emergencies within Oncologic Abdominal Surgery - What Knowledge and Skills Are Essential for the Visceral Surgeon]. / Vaskuläre Komplikationen und Notfälle in der onkologischen Viszeralchirurgie ­ was muss ein Viszeralchirurg können und wissen.

Background Continuous improvements in perioperative and neoadjuvant therapy concepts nowadays permit more extensive tumor resections with curative intention. In patients with arterial or venous tumour involvement in preoperative imaging, physicians with expertise in vascular surgery should be involved in the planning phase of the operation. Unexpected vascular complications during abdominal surgery demand prompt management by the oncological surgeon. However, skills in vascular surgery are still not obligatory for the visceral surgeon in training. This topic is controversial and is therefore the focus of the present study. Patients and Methods From 2010 - 2015, a total of 126 patients underwent visceral operations involving vascular surgical interventions. Of these, 30 operations were performed as radical tumour resections. Retrospective data acquisition was performed with a minimum follow-up of 12 months. Aside from comprehensive characterisation of patients and their diseases, an outcome analysis was conducted. Furthermore, visceral surgery training programs in accordance with all 17 German federal medical associations were analysed and compared with respect to vascular surgery teaching. Results Vascular surgery was necessary in most patients, due to lesions of the mesentericoportal venous system (n = 11; 37%) and visceral arteries (n = 14; 47%). Techniques involved were mostly vascular sutures, reanastomosis or patch plastic surgery (n = 19; 63%) and venous thrombectomy/arterial embolectomy (n = 18; 60%). Hospital mortality was 3%. During follow-up, 33% of oncological patients died, whereas solely venous injury was an independent adverse prognostic variable (arterial vs. venous complications: HR 0.028; 95%-CI 0.002 - 0.442; p = 0.01). Skills in vascular surgery are optional for up to 12 months within visceral surgery training. Conclusions Intraoperative vascular complications in visceral surgical oncology are rare but pose severe risks for the patients. Their management requires basic knowledge and skills in vascular anatomy, preparation and skills to ensure immediate safe control of bleeding, as well as suture techniques and interposition grafts. Current training and specialisation in visceral surgery does not include obligatory vascular surgery teaching, so that this issue needs reevaluation.

0.125 mm(3) spatial resolution steady-state MR angiography of the thighs with a blood pool contrast agent using the quadrature body coil only at 1.5 Tesla.

PURPOSE: To implement and evaluate high spatial resolution three-dimensional MR contrast-enhanced angiography (3D-CEMRA) of the thighs using a blood pool contrast agent (BPCA) using the quadrature body coil only in patients with peripheral arterial occlusive disease (PAOD) in cases receiver coils cannot be used at 1.5 Tesla (T). MATERIALS AND METHODS: Nineteen patients (mean age: 68.7 ± 11.2 years; range, 38-83 years) with known PAOD (Fontaine stages; III: 16, IV: 3) prospectively underwent 3D-CEMRA at 1.5T with a noninterpolated voxel size of 0.49 × 0.49 × 0.48 mm(3) . Digital subtraction angiography (DSA) was available for comparison in all patients. Two readers independently evaluated movement artifacts, overall image quality of 3D-CEMRA, and grade of stenosis as compared to DSA. SNR and CNR levels were quantified. RESULTS: The 3D-CEMRA was successfully completed in all patients. Patient movement artifacts that affected stenosis grading occurred in 3/38 thighs. Overall image quality was rated excellent in 15/38, good in 12/38, and diagnostic in 8/38 thighs. Stenosis grading matched with that in DSA in 35/38 thighs. High SNR and CNR were measured in all vessels. CONCLUSION: The 0.125 mm(3) spatial resolution 3D-CEMRA of the thighs with a BPCA is feasible using a quadrature body coil exclusively with excellent image quality despite long acquisition times. J. Magn. Reson. Imaging 2014;40:996-1001. © 2014 Wiley Periodicals, Inc.

[Indications and surgical strategy for bowel resection in mesenteric ischemia : Resection margins considering current guidelines and literature as well as the influence of new technical possibilities]. / Indikation und Operationsstrategie zur Darmresektion bei Mesenterialischämie : Resektionsgrenzen unter Berücksichtigung aktueller Leitlinien und Literatur sowie des Einflusses neuer technischer Möglichkeiten.

Acute mesenteric ischemia (AMI) is still a time-critical and life-threatening clinical picture. If exploration of the abdominal cavity is necessary during treatment, an intraoperative assessment of which segments of the intestines have a sufficient potential for recovery must be made. These decisions are mostly based on purely clinical parameters, which are subject to high level of uncertainty. This review article provides an overview of how this decision-making process and the determination of resection margins can be improved using technical aids, such as laser Doppler flowmetry (LDF), indocyanine green (ICG) fluorescence angiography or hyperspectral imaging (HSI). Furthermore, this article compiles guideline recommendations on the role of laparoscopy and the value of a planned second-look laparotomy. In addition, an overview of strategies for preventing short bowel syndrome is given and other aspects, such as the timing and technical aspects of placement of a preternatural anus and an anastomosis are highlighted.

Prognostic factors for the long term outcome after surgical celiac artery decompression in MALS.

BACKGROUND: The median arcuate ligament syndrome (MALS) is a rare disease caused by compression of the celiac artery (ORPHA: 293208). Surgical treatment of MALS aims to restore normal celiac blood flow by laparoscopic celiac artery decompression. However, surgical success rates vary widely between patients, therefore adequate selection of patients is essential to improve surgical outcome. Symptoms of MALS might also overlap with other chronic multi-system disorders such as mast cell activation syndrome (MCAS). So far, no clinical or radiological parameter was found to be predictive of the postoperative outcome. We, therefore, aim to study preclinical parameters in one of the largest MALS cohorts with the focus to identify patients that would benefit from surgical MAL release. RESULTS: By analyzing 20 MALS patients that underwent surgical celiac artery decompression, we found 60% of patients (12/20) had a postoperative relief of their symptoms and a simultaneous decrease of analgetic use. No demographic, radiologic or operative parameter was able to predict postoperative symptom relief. However, mast cell activation syndrome correlated significantly (p = 0.04) with persistent symptoms after the operation. CONCLUSIONS: Overall, laparoscopic MAL release can provide immediate symptomatic relief. Despite the missing predictive value of demographic and imaging data, our data show a correlation between persistent symptoms and a co-existing mast cell activation syndrome. This suggests that MCAS symptoms might be interpreted as MALS symptoms in the presence of celiac artery stenosis and therefore surgical treatment should be evaluated carefully. Overall, the selection of patients who are most likely to respond to surgical MAL release may best be accomplished by an interdisciplinary team of gastroenterologists, radiologists and surgeons.

Simultaneous MR arteriography and venography with blood pool contrast agent detects deep venous thrombosis in suspected arterial disease.

OBJECTIVE: The purpose of this study was to investigate the prevalence of incidental deep venous thrombosis (DVT) in patients with clinically suspected peripheral arterial occlusive disease (PAOD) using contrast-enhanced MR angiography (MRA) with a blood pool contrast agent. SUBJECTS AND METHODS: Two hundred fifty-nine MRA examinations with blood pool contrast agent in 245 consecutive patients (161 men; age range, 36-92 years), yielding a total of 4102 assessable arterial and venous vessel segments, were assessed with regard to the rate of incidentally observed acute and organized DVT and arterial stenosis grades. Incidental DVT was confirmed using duplex ultrasound. Contralateral nondiseased veins served as internal controls. The relationship between PAOD stages and acute and organized DVT was investigated using chi-square tests and a Mann-Whitney U test. RESULTS: Arterial stenosis grading using MRA with blood pool contrast agent revealed less than 50% luminal stenosis in 78% of segments (3199/4102), 50% or greater stenosis in 8% of segments (317/4102), and occlusion in 14% of segments (586/4102). Incidental DVT was observed in 26 of 245 patients (11%) (acute DVT was seen in 10 patients and 26 segments; organized DVT was seen in 17 patients and 35 segments; and one patient had both acute and organized DVT). All incidentally diagnosed cases of DVT were confirmed by duplex ultrasound. Internal controls revealed no false-positive or -negative findings (26 patients and 172 segments). Incidental acute DVT was significantly more common among patients without arterial stenosis greater than 50% (p < 0.05). Otherwise, there was no significant relationship between Fontaine PAOD stages and the occurrence of acute (p = 0.688) or organized (p = 0.995) DVT. CONCLUSION: Incidental DVT was prevalent in 11% of patients with clinically suspected PAOD. MRA with blood pool contrast agent has a potential role in the simultaneous assessment of arteries and veins and can detect concomitant venous disease affecting therapeutic management.

Visceral artery aneurysms: evolving interdisciplinary management and future role of the abdominal surgeon.

BACKGROUND: Visceral artery aneurysms (VAA) are rare vascular lesions. Clinically silent VAA are increasingly detected by cross-sectional imaging but some lesions are at risk for rupture with severe bleeding. The aim of the present study was to evaluate the trends in the interdisciplinary management at a tertiary center. METHODS: Patients who underwent treatment for VAA at University Hospital of Bonn between 2005 and 2018 were enrolled in this retrospective study. Demographic, clinical, VAA-specific data as well as information on therapy, early and long-term outcome were collected and statistically analyzed. RESULTS: Forty-two consecutive patients, 19 females and 23 males with a median age of 59 years (range 30-91 years), were diagnosed with 56 VAA. The majority were true aneurysms (N = 32; 57%), whereas 43% (N = 24) were pseudoaneurysms. The most common localization was the splenic artery (N = 18; 32%) and the average diameter was 3 cm (range 1-5 cm). Twenty-five patients (59.5%) had VAA-related symptoms such as chronic abdominal pain and hemorrhage at primary diagnosis, while the diagnosis was incidental in 17 patients (40.5%). Eleven patients (26%) underwent open surgery whereas 29 patients (69%) received an endovascular treatment. Patients with pseudoaneurysms were significantly older (P = 0.003), suffered more often from associated symptoms (P < 0.001) and required more emergency interventions (P < 0.0001) compared to those with true VAA. In the last years, the number and proportion of true VAA increased significantly (P < 0.001) while a significantly larger proportion could be managed interventionally (P = 0.017). CONCLUSIONS: VAA are increasingly detected on imaging with lesions presenting very heterogeneously. Due to the risk of lethal rupture and in the absence of reliable prognostic markers, all the patients with VAA should be offered definite treatment. Localization, anatomy and the end-organ perfusion after intervention or operation are the most important aspects to consider when planning a treatment for VAA. For this reason, a multidisciplinary evaluation of every individual patient is necessary for an optimized outcome.

Peripheral MR angiography with blood pool contrast agent: prospective intraindividual comparative study of high-spatial-resolution steady-state MR angiography versus standard-resolution first-pass MR angiography and DSA.

PURPOSE: To prospectively compare the accuracy of high-spatial-resolution steady-state magnetic resonance (MR) angiography with standard-resolution first-pass MR angiography in the lower extremities, with digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: Institutional ethics committee approval and written informed consent were obtained. Twenty-seven patients (16 men, 11 women; mean age, 64.4 years +/- 14.8 [standard deviation]; range, 26-87 years) suspected of having or known to have peripheral arterial disease underwent first-pass and steady-state MR angiography and DSA. First-pass and steady-state MR angiography were performed in the same patient in the same session and with the same dose of blood pool contrast agent. The most severe stenosis grade of each evaluated segment was measured; sensitivity, specificity, and positive and negative predictive values were calculated at first-pass and steady-state MR angiography, with DSA as the reference standard. The kappa coefficient was used to measure the agreement between first-pass MR angiography, steady-state MR angiography, and DSA. RESULTS: A total of 334 arterial segments were available for intraindividual comparison of first-pass MR angiography, steady-state MR angiography, and DSA in 27 patients. In 20 (74%) of 27 patients, the stenosis grade of at least one of the evaluated vessels differed at steady-state MR angiography from that at first-pass MR angiography. In total, stenosis grade was judged as higher at first-pass MR angiography than at DSA (overestimation) in 28 of 334 segments and as lower (underestimation) in 15 of 334 segments. The stenosis grade as judged at steady-state MR angiography matched with that at DSA in 334 of 334 vessel segments. CONCLUSION: High-spatial-resolution steady-state MR angiography allowed for better agreement with DSA regarding stenosis grade in patients with arterial disease compared with standard-resolution arterial-phase first-pass MR angiography.

Mapping of autogenous saphenous veins as an imaging adjunct to peripheral MR angiography in patients with peripheral arterial occlusive disease and peripheral bypass grafting: prospective comparison with ultrasound and intraoperative findings.

BACKGROUND: Mapping of the great saphenous vein is very important for planning of peripheral and coronary bypass surgery. This study investigated mapping of the great saphenous vein as an adjunct to peripheral MR angiography using a blood pool contrast agent in patients who were referred for evaluation of peripheral arterial occlusive disease and bypass surgery. METHODS: 38 patients with peripheral arterial occlusive disease (21 men; mean age: 71 years, range, 44-88 years) underwent peripheral MR angiography using the blood pool contrast agent Gadofosveset trisodium. Apart from primary arterial assessment images were evaluated in order to determine great saphenous vein diameters at three levels: below the saphenofemoral junction, mid thigh and 10 cm above the knee joint (usability: diameter range: >3 and <10 mm at one level and >3.5 and <10 mm at a neighboring level). Duplex ultrasound was performed by an independent examiner providing diameter measurements at the same levels. Additionally, vessel usability was determined intraoperatively by the vascular surgeon during subsequent bypass surgery. RESULTS: Mean venous diameters for MR angiography/duplex ultrasound were 5.4±2.6/5.5±2.8 mm (level 1), 4.7±2.7/4.6±2.9 mm (level 2) and 4.4±2.2/4.5±2.3 mm (level 3), respectively, without significant differences between the modalities (P = 0.207/0.806/0.518). Subsequent surgery was performed in 27/38 patients. A suitable saphenous vein was diagnosed in 25 and non-usability was diagnosed in 2 of the 27 patients based on MR angiography/duplex ultrasound, respectively. Usability was confirmed by intraoperative assessment in all of the 24 patients that received a venous bypass graft in subsequent bypass surgery. In 1 case, in which the great saphenous vein was assessed as useable by both MR angiography and duplex ultrasound, it was not used during subsequent bypass surgery due to the patients clinical condition and comorbidities. CONCLUSION: Simultaneous mapping of the great saphenous vein as an imaging adjunct to peripheral MR angiography with a blood pool contrast agent is an alternative to additive duplex ultrasound in patients undergoing subsequent peripheral bypass grafting.

Interventional exclusion of iliac artery aneurysms using the flow-diverting multilayer stent.

PURPOSE: This study was designed to evaluate retrospectively the results of complex iliac artery aneurysm (IAA) exclusion using the Cardiatis-Multilayer-Stent. METHODS: Between October 2010 and August 2012, ten IAAs were treated in eight males (mean age 75 (59-91) years) using the Multilayer Stent. All IAA exceeded a diameter of 3 cm or were symptomatic. Follow-up (FU) examinations included CT or MR angiography, sonography, and clinical assessment up to 2 years. RESULTS: Primary stent placement was technically successful in eight of ten cases. In two cases, severe stent retraction during deployment necessitated placement of an additional stent. Immediately after stent placement, a marked reduction of flow within the sac was observed in all cases (peri-interventional mortality 0%). During FU, there were two thrombotic stent occlusions, making reintervention necessary (primary patency rate 80%, secondary patency 100%). Four IAA were completely occluded at FU, whereas the original vessel and covered branches (n = 8) were patent. In four IAA, there was still residual perfusion. In one patient, IAA diameter decreased slightly, while it remained constant in seven (mean imaging FU 195 (range 1-695) days). There were no adverse events on clinical FU (mean FU 467 (range 101-695) days). CONCLUSIONS: Other studies showed the Cardiatis-Multilayer-Stent to be a technically relatively simple treatment option for complex IAA with inadequate landing zones, especially in patients with multiple comorbidities to avoid ipsilateral IIA obstruction. However, in our series complication rate was high. Incomplete sac exclusion, stent-shortening, and thrombotic occlusion can complicate treatment, making meticulous patient selection necessary. Close imaging surveillance is mandatory especially in the early postinterventional period.

Using the multilayer stent as a supplement to EVAR in combined abdominal aortic aneurysm and iliac artery aneurysm with inadequate distal landing zone--a case report.

Combined abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) is a common condition. The recently approved Cardiatis Multilayer stent (Cardiatis, Isnes, Belgium) is an innovative stent system for peripheral aneurysm management that has been applied in several clinical cases. After deployment, the unique stent design reduces mean velocity and vorticity within the aneurysm sac, causing thrombus formation and thus exclusion of the aneurysm while the vessels branching from the aneurysm remain patent. We describe a case of combined AAA and IAA with successful endovascular aneurysm repair of the AAA and treatment of the internal iliac artery with the Cardiatis Multilayer stent at 12 months of follow-up.

Endovascular management of complex renal artery aneurysms using the multilayer stent.

Since its approval as an innovative stent system for peripheral aneurysm management in May 2009, the Cardiatis Multilayer Stent (Cardiatis, Isnes, Belgium) has been applied in several clinical cases. The unique design of this multilayer stent decreases mean velocity and vorticity within the aneurysm sac immediate and causes thrombus to form, resulting in physiological exclusion of the aneurysm from the circulation, whereas branches and collaterals sprouting from the aneurysm remain patent. Here we present a case of a complex renal artery aneurysm successfully treated with a 6×30-mm Cardiatis Multilayer Stent.

Highly undersampled supraaortic MRA at 3.0 T: initial results with parallel imaging in two directions using a 16-channel neurovascular coil and parallel imaging factors up to 16.

PURPOSE: To present the feasibility of highly undersampled contrast-enhanced MRA (CE-MRA) of the supraaortic arteries with a 16-channel neurovascular coil at 3.0 T using parallel imaging in two directions with parallel imaging factors (PIF) up to 16. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. In a prospective study, MRA protocols including PIF of 1, 2, 4, 9 and 16 yielding a spatial resolution from 0.81×0.81×1.0 mm(3) to 0.46×.46×0.98 mm(3) were acquired. In 32 examinations, image quality and vascular segments were rated independently by two radiologists. SNR estimations were performed for all MRA protocols. RESULTS: The use of high PIF allowed to shorten acquisition time from 2:09 min down to 1:13 min and to increase the anatomic coverage while maintaining or even increasing spatial resolution down to 0.46×0.46×0.98 mm(3). The larger anatomic coverage that was achieved with the use of high PIF allowed for visualization of vascular structures that were not covered by the standard protocols. Despite the resulting lower SNR using high PIF, image quality was constantly rated to be adequate for diagnosis or better in all cases. CONCLUSION: The use of high PIF yielded diagnostic image quality and allowed to increase the anatomic coverage while maintaining or even improving spatial resolution and shortening the acquisition time.

Endovascular repair of inflammatory abdominal aortic aneurysms: a valuable alternative?--Case report and review of literature.

While endovascular repair (ER) has become a routine procedure in the treatment of arteriosclerotic abdominal aortic aneurysms with a suitable configuration, only rare reports of interventional treatment of inflammatory aortic abdominal aneurysms (IAAA) exist. We present a case study of a male patient with IAAA, who presented with inflammatory thickening involving the entire circumference of the aortic vessel wall. The MRI performed 8 months after successful ER demonstrated complete regression of vessel wall induration. A patient with the appropriate anatomical configuration of IAAA should benefit from the lower morbidity and mortality of endovascular aneurysm repair (EVAR). In our view, EVAR is preferable to open surgical repair in the specific situation of IAAA.

Results of perioperative measurements of ankle-brachial index in popliteal artery entrapment syndrome.

OBJECTIVE: The purpose of this study was to demonstrate whether there is postoperative improvement in blood flow in the affected limb after surgical decompression in popliteal artery entrapment syndrome (PAES). For this purpose, the simple method of measuring Doppler ankle pressure with and without provocation was used preoperatively and postoperatively. PATIENTS AND METHODS: Doppler ankle pressure was measured preoperatively and postoperatively in neutral position (n=32) and with provocation (forced plantar flexion of the foot; n=32) in 32 limbs in 23 patients with PAES (19 men, 4 women; average age, 38.24 +/- 12.25 years) operated on between January 1, 1986, and December 31, 2000. The reference method was angiography with provocation in 18 patients and duplex ultrasound scanning in 14 patients. RESULTS: Patients were assigned to one of two groups (A and B) on the basis of ankle-brachial index (ABI) at rest. Group A (mean age, 38.19 +/- 11.60 years) included all limbs (n=24) with ABI>0.9 preoperatively, and group B (mean age, 42.39 +/- 14.38 years) comprised all limbs (n=8) with ABI<0.9. Improvement in ABI under provocation after operation (group A, P<.0001; group B, P<.0004) was highly significant. In group B there was also a highly significant difference in ABI in the neutral position before and after operation (P=.0044); this could not be demonstrated in group A. Angiography or duplex sonography postoperatively did not provide any additional information. CONCLUSION: Our results indicate that determination of ABI alone, with and without provocation, is sufficient as a postoperative follow-up examination to appraise decompression and for quality assurance of PAES. Compared with other more elaborate instrumental methods, measurement of ABI is relatively noninvasive, quick and easy to carry out, effective, and inexpensive.

Magnetic resonance angiography in the follow-up of distal lower-extremity bypass surgery: comparison with duplex ultrasound and digital subtraction angiography.

PURPOSE: The danger of limb loss as a consequence of acute occlusion of infrapopliteal bypasses underscores the requirement for careful patient follow-up. The objective of this study was to determine the agreement and accuracy of contrast material-enhanced moving-table magnetic resonance (MR) angiography and duplex ultrasonography (US) in the assessment of failing bypass grafts. In cases of discrepancy, digital subtraction angiography (DSA) served as the reference standard. MATERIALS AND METHODS: MR angiography was performed in 24 consecutive patients with 26 femorotibial or femoropedal bypass grafts. Each revascularized limb was divided into five segments--(i) native arteries proximal to the graft; (ii) proximal anastomosis; (iii) graft course; (iv) distal anastomosis; and (v) native arteries distal to the graft-resulting in 130 vascular segments. Three readers evaluated all MR angiograms for image quality and the presence of failing grafts. The degree of stenosis was compared to the findings of duplex US, and in case of discrepancy, to DSA findings. Two separate analyses were performed with use of DSA only and a combined diagnostic endpoint as the reference standard. RESULTS: Image quality was rated excellent or intermediate in 119 of 130 vascular segments (92%). Venous overlay was encountered in 26 of 130 segments (20%). In only two segments was evaluation of the outflow region not feasible. One hundred seventeen of 130 vascular segments were available for quantitative analysis. In 109 of 117 segments (93%), MR angiography and duplex US showed concordant findings. In the eight discordant segments in seven patients, duplex US overlooked four high-grade stenoses that were correctly identified by MR angiography and confirmed by DSA. Percutaneous transluminal angioplasty was performed in these cases. In no case did MR angiography miss an area of stenosis of sufficient severity to require treatment. Total accuracy for duplex US ranged from 0.90 to 0.97 depending on the reference standard used, whereas MR angiography was completely accurate (1.00) regardless of the standard definition. CONCLUSION: Our data strongly suggest that the accuracy of MR angiography for identifying failing grafts in the infrapopliteal circulation is equal to that of duplex US and superior to that of duplex US in cases of complex revascularization. MR angiography should be included in routine follow-up of patients undergoing infrapopliteal bypass surgery.