Case report: direct revascularization in acute mesenteric ischemia by an endovascular approach

BACKGROUND

Acute mesenteric ischemia is a relatively rare but life-threatening clinical condition. Outcome depends on early diagnosis and prompt intervention.

CASE PRESENTATION

A 85-year-old man and a 75-year-old woman developed acute mesenteric ischemia due to cardiac embolism. The first patient received an insufficient dose of anticoagulants for atrial fibrillation and the second patient dicontinued her anticoagulantia to avoid bleeding during a routine colonoscopy. Both patients presented with severe abdominal pain and computed tomography showed thrombus in de superior mesenteric artery. Successfulrevascularization with good clinical outcome was achieved by means of an endovascular first approach.

CONCLUSION

This case report shows that an endovascular approach - in contrast to open surgery - not only enables to revascularize main trunk lesions but can also facilitate revascularization of side branches. Endovascular treatment used to be limited to a selected group of patients without signs of bowel necrosis, but there is a tendency to initiate endovascular revascularization in all patients because it is associated with a reduced mortality, a reduced laparotomy rate and reduction in the resected length of bowel.

Shrinkage of abdominal aortic aneurysm after successful endovascular repair: results from single center study

AIM

In the literature, the behavior of the aneurysm sac after endovascular grafting has been the subject of significant speculation. It has been suggested that shrinkage of the abdominal aortic aneurysm (AAA) is different for various endografts. This study was undertaken to evaluate endograft-specific differences in aneurysm sac shrinkage and to evaluate other factors that may influence AAA shrinkage.

METHODS

Forty patients with an AAA treated with endovascular grafts with a complete 18 months follow-up and complete CT angiography (CTA) follow-up were available for analysis. All patients with a persistent endoleak, endograft migration or any other reason for intervention or conversion were excluded from this analysis. Shrinkage was defined as a reduction in the AAA diameter of 5 mm or more. Chi-squared tests were used to test whether shrinkage was different for the kind of stent graft used (Gore Excluder vs Cook-Zenith), preexistent AAA diameter (<65 mm vs =or>65 mm), and AAA status (ruptured vs non-ruptured) (two-sided; a= 0.05).

RESULTS

At 18 months after treatment, shrinkage was observed in 14 patients (52%) of the 27 patients treated with a Gore Excluder endograft and in 8 patients (62%) of the 13 patients treated with a Cook Zenith endograft (P=0.74). In 31 patients with a diameter <65 mm, shrinkage was observed in 19 patients (61%) whereas of the 9 patients with a diameter =or>65 mm, shrinkage was observed in 3 patients (33%) (P=0.253). Of the 34 patients with a non-ruptured AAA, shrinkage was observed in 18 patients (53%) versus of the 6 patients with a ruptured AAA shrinkage was observed in 4 patients (66%) (P=0.673).

CONCLUSIONS

From this study can be concluded that the influence of the endograft on shrinkage of the AAA sac might be less prominent than suggested in the literature. Furthermore, our study shows that other factors such as preexistent AAA diameter may influence AAA shrinkage after endovascular repair.

[Complications within 30 days following placement of a carotid stent with cerebral protection in patients with considerable symptomatic carotid stenosis; Erasmus MC, Rotterdam, 1999-2004]

OBJECTIVE

To describe the complications that occur within 30 days following the placement of a stent in the carotid artery in patients with considerable symptomatic carotid stenosis.

DESIGN

Retrospective.

METHOD

Data were collected on 98 patients who received a carotid stent due to symptomatic carotid stenosis of > or = 70% of the lumen at the Erasmus MC, Rotterdam, the Netherlands, in the years 1999-2004. A filter, distal occlusion balloon or the Parodi anti-embolism system was used to prevent cerebral embolism. Outcome measures were complications within 30 days following intervention.

RESULTS

Four patients were excluded in the period between diagnosis and stenting. Major complications occurred in 3 patients: 1 died due to cerebral haemorrhage and 2 experienced cerebral infarction. Transient neurological complications occurred in 4 patients who recovered completely. Dissection of the renal artery occurred in 1 patient, which necessitated a stent. Vascular damage of the internal carotid artery was not observed in any patient. The 3 major adverse events and 3 of the 4 minor adverse events occurred in the first 47 patients treated. None of the last 47 patients treated developed major adverse events.

Shrinkage of the distal renal artery 1 year after stent placement as evidenced with serial intravascular ultrasound

The objective of this study was to determine the quantitative intravascular ultrasound (IVUS) and angiographic changes that occur during 1 year follow-up after renal artery stent placement, given that restenosis continues to be a limitation of renal artery stent placement. 38 consecutive patients with symptomatic renal artery stenosis treated with Palmaz stent placement were studied prospectively. IVUS and angiography were performed at the time of stent placement and at 1 year follow-up. At follow-up, angiographic restenosis was seen in 14% of patients. The lumen area in the stent, seen with IVUS, was significantly decreased from 24+/-5.6 mm(2) to 17+/-5.6 mm(2) (p<0.001) solely due to plaque accumulation. The distal main renal artery showed a significant decrease in lumen area owing to a significant vessel area decrease from 39+/-14.0 mm(2) to 29+/-9.3 mm(2) (p<0.001) without plaque accumulation. Angiographic analysis confirmed this reduction in luminal diameter and showed that the distal renal artery diameter at follow-up was significantly smaller than before stent placement (86+/-23.0% vs 104+/-23.9% of the contralateral renal artery diameter; p=0.003). Besides plaque accumulation in the stent, unexplained shrinkage of the distal main renal artery was evidenced with IVUS and angiography 1 year following stent placement.

A precious metal alloy for construction of MR imaging-compatible balloon-expandable vascular stents

The authors developed ABI alloy, which mechanically resembles stainless steel 316. The main elements of ABI alloy are palladium and silver. Magnetic resonance (MR) images and radiographs of ABI alloy and stainless steel 316 stent models and of nitinol, tantalum, and Elgiloy stents were compared. ABI alloy showed the least MR imaging artifacts and was more radiopaque than stainless steel 316. ABI alloy has the potential to replace stainless steel 316 for construction of balloon-expandable MR imaging-compatible stents.

Three-dimensional intravascular ultrasound assessment of abdominal aortic aneurysm necks

PURPOSE

To document the accuracy of an automated analysis system for measuring lumen diameter and neck lengths of abdominal aortic aneurysms (AAAs) from intravascular ultrasound (IVUS) images and to describe additional features associated with 3-dimensional (3D) IVUS imaging.

METHODS

Twenty-two aortic aneurysms were studied with IVUS. Lumen diameters obtained using the automated analysis system were compared with manual measurements from axial IVUS scans, as were neck lengths obtained using automated analysis versus those measured with the aid of a displacement sensing device. Automated analyses were repeated by a second observer. Agreement was expressed as the coefficient of variation (CV).

RESULTS

Twenty proximal aortic, 6 distal aortic, and 3 iliac necks were available for analysis. Comparison between automated analysis and manual measurements for lumen diameter revealed a difference of 0.45 +/- 0.42 mm (mean +/- SD, Pearson's r = 0.99, p < 0.001, CV = 2.1%) and a difference of 0.05 +/- 0.12 cm (r = 0.99, p = 0.04, CV = 4.1%) for neck length. Interobserver difference for lumen diameter was 0.13 +/- 0.66 mm (r = 0.99, p < 0.001, CV = 3.4%) and 0.05 +/- 0.11 cm for length measurements (r = 0.99, p = 0.02, CV = 3.5%). The 3D IVUS imaging facilitated the identification of neck configuration.

CONCLUSIONS

Automated analysis of IVUS images allows accurate measurement of the lumen diameter of proximal and distal AAA necks and gives length measurements comparable to those of manual analysis. Longitudinal display of IVUS images aids in the elucidation of neck anatomy.

Endovascular repair of an extracranial internal carotid artery aneurysm complicated by heparin-induced thrombocytopenia and thrombosis

PURPOSE

To report the endovascular treatment of a symptomatic extracranial internal carotid artery (ICA) aneurysm that was complicated by heparin-induced thrombocytopenia and thrombosis.

METHODS AND RESULTS

After undergoing a coronary artery bypass graft procedure, a patient was diagnosed with a symptomatic, 3.5-cm ICA aneurysm by computed tomography and angiography. Via a semiclosed access, an Enduring vascular graft was inserted under controlled back bleeding from the ICA. The patient was recovering uneventfully when routine duplex scanning on the fifth postoperative day suggested multiple thrombi within the graft, which was confirmed by arteriography. Thrombectomy and local fibrinolysis were performed; however, the graft occluded the next day without causing neurological symptoms. Heparin-induced thrombocytopenia was diagnosed by enzyme-linked immunosorbent assay.

CONCLUSIONS

Endovascular repair of high cervical extracranial ICA aneurysms is feasible, and protection against intracerebral embolization can be achieved using a semiclosed technique with controlled back bleeding from the ICA during endograft deployment. However, multiple thrombi or thrombotic occlusion during the postoperative period, particularly in a patient already sensitized to heparin, should direct attention toward possible heparin-induced thrombocytopenia.

Stent placement for renal arterial stenosis: where do we stand? A meta-analysis

PURPOSE

To perform a meta-analysis of renal arterial stent placement in comparison with renal percutaneous transluminal angioplasty (PTA) in patients with renal arterial stenosis.

MATERIALS AND METHODS

Studies dealing with renal arterial stent placement (14 articles; 678 patients) and renal PTA (10 articles; 644 patients) published up to August 1998 were selected. A random-effects model was used to pool the data.

RESULTS

Renal arterial stent placement proved highly successful, with an initial adequate performance in 98% and major complications in 11%. The overall cure rate for hypertension was 20%, whereas hypertension was improved in 49%. Renal function improved in 30% and stabilized in 38% of patients. The restenosis rate at follow-up of 6-29 months was 17%. Stent placement had a higher technical success rate and a lower restenosis rate than did renal PTA (98% vs 77% and 17% vs 26%, respectively; P <.001). The complication rate was not different between the two treatments. The cure rate for hypertension was higher and the improvement rate for renal function was lower after stent placement than after renal PTA (20% vs 10% and 30% vs 38%, respectively; P <.001).

CONCLUSION

Renal arterial stent placement is technically superior and clinically comparable to renal PTA alone.

Inter-observer variability in the angiographic assessment of renal artery stenosis. DRASTIC study group. Dutch Renal Artery Stenosis Intervention Cooperative

OBJECTIVE

To assess inter-observer agreement in the interpretation of renal angiograms.

DESIGN

Comparison of the assessment of renal angiograms by three experienced radiologists, who evaluated the number of renal arteries and the presence, location, aspect and severity of a renal artery stenosis.

SETTING

General hospital and university hospital serving urban and rural populations.

PATIENTS

Patients with difficult-to-treat hypertension referred for diagnostic work-up; 312 angiograms with the intra-arterial digital subtraction technique were obtained from 289 consecutive patients.

MAIN OUTCOME MEASURES

Inter-observer agreement was tested for the following parameters: number of arteries per kidney, presence of stenosis, location of stenosis (truncal, ostial), aspect of stenosis (concentric, eccentric, post-stenotic dilatation), severity of stenosis (reduction of lumen diameter in categories of 30%, 40%, etc. to 100%), and overall quality of the angiographic images. Kappa (kappa) values and weighted kappa between the three pairs of radiologists were used as estimates of inter-observer agreement

RESULTS

Agreement about the number of renal arteries was reasonable (kappa = 0.50-0.72), as was agreement about the presence of stenosis (kappa = 0.68-0.86). Agreement about stenosis location and aspect was poor (kappa = 0.26-0.47 and kappa = 0.15-0.26, respectively). There was general agreement about the severity of stenosis (weighted kappa = 0.65-0.70), but it was not possible to distinguish between 50 and 60% stenosis or between 60 and 70% stenosis (kappa < 0.40). No correlation was found between agreement on severity of stenosis and the quality of the images.

CONCLUSIONS

It is not realistic to make statements about what degree of renal artery stenosis is clinically significant, as long as the intra-arterial angiogram with digital subtraction remains the gold standard. It is likewise risky to rely too strongly on stenosis morphology as visualized by renal angiography in choosing between balloon angioplasty and stent deployment.

Ultrasound-guided percutaneous coil embolization of incompetent perforating veins: not effective for treatment of venous ulcers and recurrent varicosities

PURPOSE

To investigate the feasibility of ultrasound-guided percutaneous coil embolization of incompetent perforating veins as minimally invasive treatment for venous ulcers and recurrent varicosities in the lower leg. This could be an alternative to surgical ligation of perforating veins.

MATERIALS AND METHODS

In 15 patients (six women, nine men; mean age, 50 years), 18 incompetent perforating veins in the lower leg were treated by ultrasound-guided percutaneous placement of embolization coils.

RESULTS

Successful vein occlusion with one or more coils was achieved in 12 of the 18 veins (technical success rate, 67%). Clinical symptoms improved in only three of the 15 patients (clinical success rate, 20%). During follow-up (2-12 months), recanalization of coil embolized veins occurred in nine of the 12 initially occluded veins.

CONCLUSION

Percutaneous ultrasound-guided coil embolization does not appear to be as effective as subfascial endoscopic perforator surgery in the treatment of incompetent perforator veins.

Intravascular ultrasound evidence for coarctation causing symptomatic renal artery stenosis

BACKGROUND

A recent study of human cadaveric renal arteries revealed that renal artery narrowing could be due not only to atherosclerotic plaque compensated for by adaptive remodeling, but also to hitherto undescribed focal narrowing of an otherwise normal renal arterial wall (ie, coarctation). The present study investigated whether vessel coarctation could be identified in patients with symptomatic renal artery stenosis (RAS).

METHODS AND RESULTS

Consecutive symptomatic patients with angiographically proven atherosclerotic RAS who were referred for stent placement were studied by 30-MHz intravascular ultrasound before intervention (n=18) or after predilatation (n=18). Analysis included assessment of the media-bounded area and plaque area (PLA) at the most stenotic site and at a distal reference site (most distal cross-section in the main renal artery with normal appearance). Coarctation was considered present whenever the target/reference media-bounded area was </=85%. Before intervention, coarctation was observed in 9 of 18 patients and adaptive remodeling in 9 of 18 patients. Coarctation lesions had a significantly smaller PLA than adaptive remodeled lesions (P=0.001). Similarly, despite predilatation, coarctation was seen in 8 of 18 patients who had significantly smaller PLAs (P=0. 008) when compared with those patients who had adaptive remodeled lesions. No differences in severity of RAS or angiographic or clinical parameters were observed.

CONCLUSIONS

Low-plaque coarctation may cause a considerable proportion of symptomatic RAS, which is angiographically and clinically indistinguishable from plaque-rich RAS.

Accurate assessment of abdominal aortic aneurysm with intravascular ultrasound scanning: validation with computed tomographic angiography

PURPOSE

The purpose of this study was to assess the accuracy of intravascular ultrasound (IVUS) parameters of abdominal aortic aneurysm, used for endovascular grafting, in comparison with computed tomographic angiography (CTA).

METHODS

This study was designed as a descriptive study. Between March 1997 and March 1998, 16 patients with abdominal aortic aneurysms were studied with angiography, IVUS (12.5 MHz), and CTA. The length of the aneurysm and the length and lumen diameter of the proximal and distal neck obtained with IVUS were compared with the data obtained with CTA. The measurements with IVUS were repeated by a second observer to assess the reproducibility. Tomographic IVUS images were reconstructed into a longitudinal format.

RESULTS

IVUS results identified 31 of 32 renal arteries and four of five accessory renal arteries. A comparison of the length measurements of the aneurysm and the proximal and distal neck obtained with IVUS and CTA revealed a correlation of 0.99 (P <.001), with a coefficient of variation of 9%. IVUS results tended to underestimate the length as compared with the CTA results (0.48 +/- 0.52 cm; P <.001). A comparison of the lumen diameter measurements of the proximal and distal neck derived from IVUS and CTA showed a correlation of 0.93 (P <.001), with a coefficient of variation of 9%. IVUS results tended to underestimate aneurysm neck diameter as compared with CTA results (0.68 +/- 1.76 mm; P =.006). Interobserver agreement of IVUS length and diameter measurements showed a good correlation (r = 1.0; P <.001), with coefficients of variation of 3% and 2%, respectively, and no significant differences (0.0 +/- 0.16 cm and 0.06 +/- 0.36 mm, respectively). The longitudinal IVUS images displayed the important vascular structures and improved the spatial insight in aneurysmal anatomy.

CONCLUSION

Intravascular ultrasound scanning results provided accurate and reproducible measurements of abdominal aortic aneurysm. The longitudinal reconstruction of IVUS images provided additional knowledge on the anatomy of the aneurysm and its proximal and distal neck.

Three-dimensional ultrasound study of carotid arteries before and after endarterectomy; analysis of stenotic lesions and surgical impact on the vessel

BACKGROUND AND PURPOSE

It has been proved that symptomatic patients with severe carotid stenosis benefit from endarterectomy. Currently used methods for quantitation of the severity of carotid stenosis have limitations, and the impact of endarterectomy on the operated region of carotid artery remains unknown. The purpose of this study was to examine the accuracy of a 3-D ultrasound system for quantitation of stenotic lesions and to evaluate changes in regional vessel volume and cross-sectional area after carotid endarterectomy.

METHODS

We studied 14 patients with both carotid angiography and 3-D ultrasound. Of 13 patients who underwent surgery, 12 were reexamined with 3-D ultrasound after surgery. The length and volume of 20 randomly selected plaques were measured from 3-D data sets. The severity of stenosis was quantified by 3-D ultrasound using both a diameter method and an area method on cross-sectional views at the most stenotic site; the results were then compared with those from carotid angiography. The segmental vessel volume and average cross-sectional area of the operated artery both before and after endarterectomy were measured from 3-D ultrasound data.

RESULTS

Good correlation was obtained between 3-D ultrasound and carotid angiography in quantitative analysis of carotid stenosis (SEE=12.4%, r=0.76, and mean difference=7.0+/-12.3% with the diameter method; SEE=10.5%, r=0.82, and mean difference=1.8+/-10.5% with the area method by 3-D ultrasound). 3-D ultrasound had excellent reproducibility and small intraobserver and interobserver variability in plaque length and volume measurements. No significant changes in segmental vessel volume and average cross-sectional area of the operated artery were observed after surgery in patients with suture closure. However, a significant increase in segmental vessel volume was obtained in patients with polyfluorethylene patches applied to the surgical opening of the artery.

CONCLUSIONS

3-D ultrasound can be used for both qualitative and quantitative analysis of plaques in the carotid artery and to detect and quantify significant carotid stenosis. Its volumetric potential has important clinical implications in serial follow-up studies for observing the progression or regression of stenotic lesions and for evaluating the outcome of interventional procedures such as endarterectomy or stent placement.

Residual arteriovenous fistulae after "closed" in situ bypass grafting: an overrated problem

OBJECTIVES

To prospectively evaluate the incidence and consequences of residual arteriovenous (AV)-fistulae after "closed" in situ bypass grafting.

METHODS

In 34 patients, 35 "closed" in situ bypasses were performed. Postoperative assessment of residual AV-fistulae and bypass patency was performed with duplex scanning.

RESULTS

Postoperative mortality was 3%. During 35 "closed" in situ bypass procedures 216 side branches were coil embolised. Postoperatively 39 AV-fistulae were detected (15% of the total number of 216 + 39 = 255 side branches). Of these, 13 (5%) closed spontaneously. Fifteen (6%) remained unchanged and 11 (4%) were treated. In three patients four asymptomatic residual AV-fistulae were treated. In four patients seven symptomatic AV-fistulae were treated for: decreased distal bypass flow in one; persistent leg oedema in one; pain and redness of the skin in two. One-year primary patency was 80% (SE 8.4%). Residual AV-fistulae were detected in none of six bypass occlusions during follow-up.

CONCLUSION

Residual AV-fistulae detected following "closed" in situ bypass grafting only need treatment if they are symptomatic, which is uncommon.

Comparison of cost affecting parameters and costs of the "closed" and "open" in situ bypass technique

OBJECTIVES

The "closed" in situ bypass results in a reduction of wound complications compared to the "open" technique. This advantage is partly diminished by extra costs for the "closed" procedure and a larger percentage of residual arteriovenous (AV)-fistulae. This aim of this study was to analyse costs related to "closed" and "open" procedures.

METHODS

The cost affecting parameters: (1) duration of operation; (2) length of hospital stay; and (3) number of treated residual AV-fistulae, were analysed in a randomised group of 73 patients (35 "closed" and 38 "open") in two centres. In addition, costs of the operation, nursing care and treatment of AV-fistulae were analysed.

RESULTS

The "closed" and "open" group showed a median duration of operation of 210 min (range 105-570) and 154 min (range 90-355) (p < 0.05), length of hospital stay of 16 days (range 5-51) and 25 days (range 12-65) (p < 0.01), and a percentage of patients treated for residual AV-fistulae of 40% and 5%, respectively (p < 0.01). The median "closed" operation was US$798 more expensive than the "open". Median postoperative care was US$2664 less for the "closed" group. Mean estimated costs for treatment of AV-fistulae was US$9 in the "open" and US$167 in the "closed" group.

CONCLUSION

The "closed" in situ vein bypass technique is cost-effective in comparison with the "open" technique.

The value of pre-operative ultrasound mapping of the greater saphenous vein prior to 'closed' in situ bypass operations

OBJECTIVE

The aim of this study was to test pre-operative ultrasound mapping for the detection of duplications and narrow vein segments of the greater saphenous vein (GSV) used as bypass for occlusive arterial disease surgery.

PATIENTS AND METHODS

In 44 patients pre-operative ultrasound findings of duplications and lumen assessment of GSV were compared to the per-operative findings.

RESULTS

In nine patients (20%) the pre-operative ultrasound examination showed a duplication. Pre-operative ultrasound had missed a duplication in two cases but had instead shown a narrow segment in both. The pre-operative ultrasound assessment of lumen diameter showed a narrow lumen segment in 10 of the 44 patients. In one patient a per-operatively narrow lumen had not been seen on pre-operative ultrasound.

CONCLUSION

Pre-operative ultrasound mapping of the GSV is a sensitive tool for detection of duplications and narrow vein segments. Since these anatomical variations provide important information for the vascular surgeon, before performing a 'closed' in situ bypass operation, pre-operative vein mapping should be considered when planning such a procedure.

A new "closed" in situ vein bypass technique results in a reduced wound complication rate

OBJECTIVES

This prospective randomised multicentre trial was conducted to test whether a new "closed" technique for in situ vein bypass would result in a lower frequency of wound complications, without negative effects on patency rates and without an intolerable increase in residual arteriovenous fistulae compared to the conventional "open" technique.

METHODS

We have developed a new "closed" technique using a co-axial catheter embolisation system for intra-operative coil embolisation of side branches, in order to avoid long incisions.

PATIENTS

In four centres and 95 patients, 97 in situ bypasses were performed: 47 "closed" and 50 "open". Randomisation was stratified for below knee femoropopliteal bypasses (60) and femorocrural bypasses (37). Indications were disabling intermittent claudication (29), restpain (26) or ulcers and/or necrosis (42).

RESULTS

Postoperative mortality was 2% (one in the "closed", one in the "open" group). A total number of 16 (34%) wound complications (grade 1, 2 and 3) occurred in the closed group compared to 36 (72%) in the open group (p < 0.05). Deep wound complications (grade 2) occurred in six patients (13%) of the "closed" group, compared to 15 (30%) in the "open" group. In both groups, three patients (6%) developed deep wound complications including the bypass area (grade 3). In the "closed" group, 20 patients needed additional treatment for arteriovenous fistulae, compared to four in the "open" group. One-year patency rates did not show a statistically significant difference: primary patency rates were 65% and 61% and secondary patency rates were 86% and 76% respectively for the "closed" and "open" group.

CONCLUSION

These results indicate that a "closed" technique reduces wound complication rate, without negative effects on the short term patency rates. The "closed" technique results in an increased number of postoperative treatments for residual arteriovenous fistulae.

Assessment of stenoses in the aortoiliac tract by calculation of a vascular resistance change ratio before and after exercise

OBJECTIVES

Intraarterial pressure measurement is the most reliable method to assess haemodynamically significant stenoses in the aortoiliac tract. We have tried to develop a simple and quick, non-invasive method to assess stenoses of this type.

DESIGN

Prospective semi-blinded clinical study.

METHODS

It was postulated that a haemodynamically significant aortoiliac tract stenosis would result in a lesser degree of vascular resistance decrease after vasodilatation, compared to patients only suffering from femorodistal stenoses. We approximated vascular resistance by: (brachial pressure-ankle pressure)/femoral artery mean Doppler velocity. By dividing vascular resistance at rest by vascular resistance after exercise, we calculated the Resistance Change Ratio (RCR).

PATIENTS AND RESULTS

In 34 patients (50 legs) with arterial stenoses, the pressure gradient over the aortoiliac segment was compared to the RCR. Legs were divided in three groups: group 1 consisted of 22 legs that showed a pressure gradient > 10 mmHg at rest; group 2 showed a pressure gradient > 10 mmHg after papaverine; group 3 showed a pressure gradient of 10 mmHg or less. The median RCR was: 0.74 (range: 0.23-4.04) for group 1, 0.71 (range: 0.36-1.80) for group 2 and 0.93 (range 0.36-2.06) for group 3. There was no significant difference between the groups (p = 0.19).

CONCLUSION

The RCR could not be used to accurately detect stenoses in the aortoiliac.

A new "closed" in situ vein bypass technique

AIM

We have developed a new closed technique using a co-axial catheter embolisation system for intraoperative coil embolisation of the side branches of in situ vein bypass grafts in order to avoid long skin incisions.

TECHNIQUE

After completion of the proximal anastomosis, disruption of the valves and completion of the distal anastomosis, the catheter is introduced via a proximal side branch of the greater saphenous vein. Under fluoroscopic control the side branches are identified, selectively catheterised and an embolisation coil is positioned in each side branch.

PATIENTS

In 14 patients (eight men, six women), 16 in situ bypasses were performed (12 below knee femoro-popliteal, four femoro-crural).

RESULTS

Once mastered the embolisation procedure took less than 1 hour. In four cases persistent arteriovenous fistulae had to be treated in the postoperative period. Two major wound complications occurred and there were three early failures. One late failure occurred due to a rupture of the venous bypass 6 weeks postoperatively. The remaining 12 bypasses are patent, with a median follow-up of 16 (3-26) months.

CONCLUSION

These preliminary results suggest that the "closed" technique is feasible and that long term occlusion of AV-fistulae can be achieved without ligation via incisions.

Intravascular ultrasonography before and after intervention: in vivo comparison with angiography

PURPOSE

To compare the additional capacity of intravascular ultrasonography versus angiography to assess morphologic features and lumen dimension, 37 patients undergoing vascular intervention of the common iliac or superficial femoral artery were studied. A total of 181 ultrasonic cross sections were analyzed (94 before and 87 after intervention).

METHODS AND RESULTS

Before intervention intravascular ultrasonography distinguished normal cross sections (n = 17) from cross sections with a lesion (n = 77): soft (51%) versus hard (31%) lesions, and eccentric (75%) versus concentric (7%) lesions. After intervention intravascular ultrasonography documented dissection (43%), plaque rupture (10%), and internal elastic lamina rupture (8%). A good correlation between ultrasonography and angiography was found for the recognition of eccentric or concentric lesions and dissections. The degree of stenosis was assessed semiquantitatively by visual estimation of the degree of luminal narrowing from the angiograms and intravascular ultrasonic images and was categorized into four classes: (1) normal, (2) less than 50% stenosis, (3) 50% to 90% stenosis, and (4) greater than 90% stenosis. Intravascular ultrasonographic assessment of stenosis was in agreement with angiography in 78% of cases and showed more severe lesions in 22% before intervention. Similar data were observed after intervention, with 72% of results being in agreement and 28% of cases showing more severe lesions. The degree of stenosis was also quantitatively evaluated by computer-aided analysis of the intravascular ultrasonic images. The semiquantitative analysis by intravascular ultrasonography corresponded well with the quantitative analysis done by the computer-aided system. When both echography and angiography suggested that arteries were normal, quantitative intravascular ultrasonography identified lesions that occupied an average of 18% of the cross-sectional area of the vessel.

CONCLUSIONS

This in vivo study shows that intravascular ultrasonography is capable of documenting detailed morphologic features. Semiquantitative ultrasonic data correlate closely with those of angiography, albeit stenoses were assessed as more severe on ultrasonography.

[Hemobilia, a rare and difficult diagnosis]

Haemobilia, i.e. blood loss via the bile ducts, is a rare disorder, which may be caused by trauma, vascular disorders, gallstones, infection/inflammation, tumours and coagulation disorders. Haemobilia may cause grave morbidity and mortality. Important symptoms are: gastrointestinal bleeding, jaundice and colicky pains in the right upper abdominal quadrant. Gastroduodenoscopy, ultrasound, ERCP, CT-scan and MRI may be used to obtain additional information when haemobilia is suspected. Selective angiography may provide detailed information of the bleeding, but is less appropriate as an initial screening method. Haemobilia may be treated by selective embolisation of the involved artery or by operative treatment. Embolisation is the treatment of first choice in most situations. We present a case report of a patient with recurrent haemobilia caused by a ruptured aneurysm of a hepatic artery leaking intermittently into the bile ducts. Partly because of the rareness of this syndrome, the disorder was recognized with delay in our patient. After two embolisation attempts had failed, he was treated successfully by obliterative endoaneurysmorrhaphy.