Stent grafts for aortic aneurysms: the next interventional challenge.

Stent grafts (endografts) have proved useful for the endoluminal exclusion of peripheral and aortic aneurysms, both those in native arteries and those resulting from prior surgery. In addition, their use may apply in some patients with occlusive vascular disease. Various types of endografts are being evaluated in clinical trials, including those that utilize unsupported grafts with stentlike attachment mechanisms and those having a metallic endoskeleton or exoskeleton. Relatively complex devices can be delivered through small arteriotomies and in some cases percutaneous approaches. Unsupported grafts, although more prone to kinking and incomplete expansion, appear to work well. Some devices employ modularity, which involves separate placement of contralateral limbs and, in some cases, extension devices. For performing endovascular grafting, pretreatment planning is critical and requires sophisticated imaging, including spiral computed tomography (CT) with 3-dimensional reconstruction and angiographic evaluation using catheters with calibrated markers. Potential advantages of endovascular grafts include a decreased hospital stay, a less invasive procedure, and lower morbidity and mortality. Several issues remain unresolved and should be addressed by the newer generation of these devices.

Persistently increased expression of the transforming growth factor-ß1 gene in human vascular restenosis: Analysis of 62 patients with one or more episode of restenosis.

Transforming growth factor-beta-1 (TGF-ß1) is a multifunctional cytokine with both growth-promoting and growth-inhibiting properties. Moreover, there is abundant evidence that TGF-ß1 is the principal growth factor responsible for regulating proteoglycan synthesis in human blood vessels. To determine the potential contribution of TGF-ß1 to restenosis, the current investigation sought to determine the time course of expression postangioplasty of the TGF-ß1 gene. In situ hybridization was performed on tissue specimens obtained by directional atherectomy from 62 patients who had previously undergone angioplasty of native coronary or peripheral arteries and/or saphenous vein bypass grafts. The time interval between angioplasty and atherectomy was 1 hour to 25 months (M ± SEM = 5 ± 4 months) for all 62 patients, 5 ± 4 months for coronary arterial specimens, 8 ± 5 months for vein graft specimens, and 7 ± 3 months for peripheral arterial specimens. TGF-ß1 mRNA expression remained persistently increased independent of the site from or time interval following which the specimen was obtained. For saphenous vein by pass grafts, TGF-ß1 expression was highest in specimens retreived from patients with multiple versus single episodes of restenosis (16 ± 5 vs. 6 ± 5 grains/nucleus, p < 0.01). TGF-ß1 expression did not correlate with patient age, sex, or known risk factors for coronary heart disease. The persistently augmented expression of TGF-ß1 observed in the present series of restenosis lesions provides further support for the concept that TGF-ß1 influences growth and development of restenosis plaque.

Postoperative management: type I and III endoleaks.

The purpose of this article is to help the reader understand the importance of imaging findings and treatment strategies for type I and III endoleaks. Although the appearance of these leaks on computed tomography can be somewhat unremarkable and similar in appearance to type II endoleaks, it is critically important for the treating physician to make the correct diagnosis, as these endoleak types signify an incompletely treated aneurysm. Once the diagnosis of a type I or III endoleak is made, the next step in treatment is to identify the cause of the endoleak. Incomplete initial graft expansion, further arterial dilation, endograft migration, component separation, and tears within the graft fabric are all possible causes of type I and III endoleaks. A combination of computed tomography, plain film radiography, and diagnostic angiography may be necessary to make the diagnosis and identify the underlying cause of the complication. Once all of these factors have been determined, a decision has to be made of whether the endoleak can be treated through additional endovascular means or if endovascular therapy has failed for the patient, making open surgical revision necessary to treat the aneurysm. Illustrative cases of all endoleak types and their treatments are the focus of this article.

Postoperative management: buttock claudication and limb thrombosis.

As a result of endovascular repair of abdominal aortic aneurysms and the necessary associated adjunctive procedures, postoperative buttock claudication and limb thrombosis are complications that every physician who implants stent-grafts should be able to recognize and treat. Whereas the presenting complaints of these complications can be quite obvious, the treatment of them may be not so simple. Studies have shown that 28% of patients who underwent embolization of one or both hypogastric arteries develop buttock claudication. Yet 78% of these affected patients spontaneously resolve their symptoms. Strategies to both minimize and successfully treat this complication are obviously of the utmost importance. Likewise, limb thrombosis can be easy to recognize, but treatment strategies and methods to limit this complication can be quite complex and remain somewhat controversial. One center was able to reduce their limb thrombosis rate from 17% to 0% through the use of intravascular ultrasound and aggressive adjunctive stenting. The purpose of this article is to first review the data concerning these complications and then to discuss treatment strategies that are designed to minimize and treat the actual complication.

Compact contrast material bolus with a new 5-F angiographic catheter.

The conventional pigtail catheter was compared with the 5-F Tennis Racquet catheter for abdominal aortography with digital subtraction angiography. Resulting aortograms were judged on the basis of the quality of aortic opacification and renal artery visualization. The authors concluded that the Tennis Racquet catheter produces a more compact contrast material bolus, and its use is associated with acquisition of superior abdominal aortograms.

The role of sonography and transhepatic cholangiography in the diagnosis of biliary complications after liver transplantation.

We retrospectively reviewed the results of real-time sonography in 41 patients in whom biliary complications after liver transplantation were documented by percutaneous transhepatic cholangiography. Abnormalities included bile duct stricture (26 cases), occluded internal biliary stent (six cases), common duct redundancy with resultant functional biliary obstruction (three cases), bile leak (three cases), choledocholithiasis (two cases), and an abscess in a cystic duct remnant (one case). Sonography was abnormal in 22 of the 41 cases (sensitivity, 54%). Bile duct dilatation was the positive sonographic finding in 19 (86%) of the 22 abnormal examinations. In the remaining 19 patients, sonography was normal. Sonography is not a reliable test for the early detection of biliary abnormalities after liver transplantation. Percutaneous transhepatic cholangiography should be performed in patients with suspected biliary complications after liver transplantation.

The cause of superior vena cava syndrome: diagnosis with percutaneous atherectomy.

The cause of superior vena cava syndrome (SVCS) in two patients was identified by means of endovascular biopsy of the superior vena cava (SVC) performed with a percutaneous atherectomy catheter. In both cases, the extracted tissues were neoplastic, therefore obviating additional invasive procedures. After a specific diagnosis was established, external-beam radiation therapy was used to treat the SVCS. The atherectomy catheter was used in conjunction with other percutaneous techniques, including balloon angioplasty and endovascular stenting of the SVC.

Neutralized lidocaine: use in pain reduction in local anesthesia.

The effect of pH neutralization on the pain experienced during intradermal lidocaine administration was investigated in a prospective blind study of 20 adult volunteers. A plain solution (pH congruent to 6.1) and three different buffered solutions of 1% lidocaine (pH values of 6.8, 7.0, and 7.2) were prepared, and a 0.5-mL intradermal injection of each was administered to the volar aspect of the forearm. Pain associated with lidocaine infiltration was rated with a linear visual analogue scale. Solutions with a pH of less than 6.8 (unbuffered lidocaine in this study) predictably produced a burning pain sensation on injection. However, buffering of 1% lidocaine above a pH of 6.8 significantly (P less than .05) reduced the mean quantitative pain estimates compared with the nonbuffered controls.

Technical advances in transjugular intrahepatic portosystemic shunts.

A transjugular intrahepatic portosystemic shunt (TIPS) can be created percutaneously with the Palmaz balloon-expandable stent. This article describes a transjugular-only approach with a 16-gauge needle. A functional and efficacious shunt can be achieved in most cases with stent diameters of 8-10 mm. Occasionally, a 12-mm-diameter shunt is necessary for effective variceal decompression. The procedure is considered successful when the portosystemic gradient is lowered to 12 mm Hg or less after stent placement. Hepatic vein stenosis in the shunt outflow can develop after the TIPs procedure. This complication has been treated successfully with additional stent placement. TIPS can undoubtedly be performed successfully and safely with a transjugular-only approach; however, the full impact of TIPS on the treatment of portal hypertension remains to be determined.

Percutaneous transjugular portosystemic shunt.

OBJECTIVE: --To determine the effectiveness of the Palmaz balloon expandable stent for the creation of a transjugular intrahepatic portosystemic shunt. The device is designed to achieve portal decompression in patients with variceal hemorrhage secondary to portal hypertension. DESIGN: --Transjugular intrahepatic portosystemic shunting was performed in eight patients during a 9-month period. Mean follow-up was 5 months. PATIENTS: --All patients had cirrhosis with portal hypertension and varices. Bleeding occurred in seven patients from esophageal varices and in one patient from hemorrhoids. MAIN OUTCOME MEASURES: --Shunt patency and recurrent variceal hemorrhage. RESULTS: --Shunts created from a transjugular approach between a hepatic and a portal vein (diameters of 8 to 12 mm) lowered the average portosystemic pressure gradient from 36 to 11 mm Hg. Mean postoperative hospital stay was 7.7 days. Complete variceal decompression after transjugular intrahepatic portosystemic shunt placement was identified endoscopically in all eight patients. The patient treated for hemorrhoids rebled and was treated successfully by transfemoral balloon expansion of the shunt diameter from 8 to 12 mm. All shunts were patent at 1 to 9 months (mean, 5 months) of follow-up. CONCLUSION: --Initial results suggest that transjugular intrahepatic portosystemic shunt is a safe and effective method of portal decompression for the treatment of variceal hemorrhage.

Directional atherectomy in the treatment of stenotic dialysis access fistulas.

Directional atherectomy has proved useful in the treatment of peripheral vascular occlusive disease, and the authors have begun using this modality in the treatment of patients with failing hemodialysis access fistulas. The authors describe their initial experience with 13 patients in whom directional atherectomy was used to treat stenotic hemodialysis fistulas. Directional atherectomy was the sole treatment modality for eight patients. Three patients underwent atherectomy after unsuccessful percutaneous transluminal angioplasty (PTA). In two patients, unsuccessful atherectomy necessitated subsequent PTA. Directional atherectomy was successful in 10 of 13 patients. In seven of these 10 patients who are still alive, the dialysis fistulas remain patent. Directional atherectomy is a safe and useful technique in the percutaneous treatment of hemodialysis fistula stenosis. Early data indicate patency rates that may be higher than those reported with PTA.

Low-dose urokinase regimen for the treatment of lower extremity arterial and graft occlusions: experience in 132 cases.

In a retrospective review, a low-dose urokinase (UK) infusion regimen (mean, 87,000 U of UK per hour and 100 U of heparin per hour) was evaluated for lower extremity arterial and graft occlusions. Results of 132 infusions in 111 patients were analyzed to determine efficacy, limb salvage, and complications. Angiographic success was achieved with 126 infusions (95%), and amelioration of presenting signs and symptoms was achieved after 116 infusions (88%). Patients who underwent additional percutaneous procedures were more likely to have a successful outcome. There was no significant difference in success rates for patients receiving low-dose heparin through the arterial sheath (n = 101) versus those receiving concomitant systemic heparinization (n = 29), (P = .08) [corrected]. Of 88 threatened extremities (with rest pain, cold, ulcers, or gangrene), nine were amputated (limb salvage = 90%), accounting for 82% (nine of 11) of amputations in the overall study. Patients with zero- or one-vessel runoff before infusion were more likely to require limb amputation compared with the group with two- or three-vessel runoff before infusion (P less than .01). Major periprocedural complications occurred in nine of 132 (7%) infusions, five of which necessitated specific surgery and/or transfusion for bleeding. Pericatheter thrombosis was not encountered in either subgroup. This standard local low-dose infusion represents a safe and effective treatment for lower extremity arterial and graft occlusions.

Percutaneous angioplasty for atherosclerotic renal artery disease: effect on renal function in azotemic patients.

PURPOSE: We studied the effect of percutaneous transluminal renal angioplasty (PTRA) on renal function in azotemic patients with atherosclerotic renal artery stenosis. METHODS: The results of PTRA were analyzed retrospectively in 40 patients. There were 61 stenoses, 54 of which received balloon angioplasty; 7 had stent placement during the initial procedure, 6 for recurrent stenosis 6-18 months after PTRA. RESULTS: Technical success was achieved in 95% of cases. The complication rate was 15%, compared to 6% in nonazotemic patients. Mean creatinine rose from 1.9 +/- 0.15 mg/dl (mean +/- SEM) to 2.4 +/- 0.17 mg/dl during the year before PTRA, stabilizing at 2.5 +/- 0.57 mg/dl for 1 year after PTRA. PTRA was clinically successful in 60% of patients; 40% showed further deterioration of renal function. Clinical failure was associated with residual renal artery stenosis and presence of intermittent claudication. CONCLUSION: We conclude that PTRA helps salvage renal function in patients with azotemia and atherosclerotic renal artery stenosis.

Initial results of reteplase in the treatment of acute lower extremity arterial occlusions.

PURPOSE: To assess the feasibility and efficacy of reteplase in transcatheter arterial thrombolysis for lower extremity occlusive disease. MATERIALS AND METHODS: Fifteen consecutive patients with acute lower extremity ischemia due to occlusive disease were treated by means of catheter-directed thrombolysis with reteplase. Following diagnostic angiography, thrombolysis was started either from an antegrade puncture site in cases of femoropopliteal occlusions, or from the contralateral groin in cases of thrombosis of the iliac artery, common femoral artery, or infrainguinal bypass grafts. Reteplase was infused at a rate of either 0.5 U/h (six patients) or 1.0 U/h (nine patients). RESULTS: Complete thrombolysis was achieved in all of the nine (100%) patients in the 1.0 U/h group and in four of six (66%) patients in the 0.5 U/h group for a combined success rate of 13 of 15 (87%). Clinical success was achieved in 11 of 15 patients overall (73%). Major bleeding complications occurred in none of the 9 patients in the 1.0 U/h group and in one (16%) of the six patients in the 0.5 U/h group for an overall rate of 6%. CONCLUSIONS: Reteplase shows promise as an alternative to urokinase in the treatment of lower extremity ischemia due to arterial occlusive disease.

May-Thurner syndrome in an adolescent: persistence despite operative management.

We describe a patient with May-Thurner syndrome who underwent operative transection and transposition of the right common iliac artery without direct venous repair, because preoperative and intraoperative intravascular ultrasound scans were negative for "spurs" in the left common iliac vein. When symptoms and signs persisted, a postoperative magnetic resonance venogram (MRV) showed severe stenosis in the left common iliac vein. Progressive, but incomplete, clinical improvement occurred with conservative management.

Synthetic dialysis shunts: thrombolysis with the Cragg thrombolytic brush catheter.

PURPOSE: To evaluate the effectiveness of the Cragg thrombolytic brush catheter for declotting of synthetic arteriovenous dialysis shunts. MATERIALS AND METHODS: In this randomized controlled trial, 77 patients with synthetic forearm loop shunts that were thrombosed were randomly assigned to undergo pharmacomechanical thrombolysis with a pulsed spray (n = 34) or a thrombolytic brush catheter (n = 43). The following findings were evaluated: declotting time, urokinase dose, procedure time, complications, and shunt patency at the first dialysis session and at 3 months. All data were collected prospectively in an unblinded manner. RESULTS: The total amount of urokinase used, including secondary interventions, was 243,657 IU with the catheter versus 476,563 IU with the pulsed spray (P = .001). At 15 minutes, clot lysis was successful in 66% of the patients with the catheter versus in 19% with the pulsed spray (P = .001). At 30 minutes, clot lysis was successful in 98% with the catheter versus 47% with the pulsed spray (P = .001). Procedure complication rates and patency at 3 months were similar for the catheter and the pulsed-spray groups. CONCLUSION: Use of the Cragg catheter with urokinase offered faster and more complete clot lysis than did use of the pulsed spray with urokinase. The amount of urokinase used with the catheter was half that used with the pulsed spray. Shunt patency at 3 months was similar for the two treatment methods.

Percutaneous placement of a balloon-expandable intraluminal graft for life-threatening subclavian arterial hemorrhage.

A balloon-expandable intraluminal graft was percutaneously deployed in the left subclavian artery of a 43-year-old woman. This graft was made of a stainless steel, 30-mm Palmaz balloon-expandable iliac stent completely covered with a thin coat of silicone. The procedure was successful in managing and preventing life-threatening hemorrhage as a large-bore catheter was removed from the subclavian artery via its subcutaneous tunnel. Surgical repair of the high brachial-axillary sheath insertion site was required after percutaneous deployment of the graft. However, the grafting procedure succeeded in obviating a thoracotomy. At follow-up of 6 months, despite diminution in brachial pulse volume recordings, the patient is asymptomatic at rest. She experiences mild fatigue with extremes of upper extremity exercise and declines angiographic follow-up and further intervention.

The influence of female gender on the outcome of endovascular abdominal aortic aneurysm repair.

PURPOSE: Women appear to have a greater risk of death than men after open surgery for abdominal aortic aneurysm (AAA). The aim of this study is to compare outcomes after endovascular AAA repair in men and women. MATERIALS AND METHODS: From March 1994 to November 2000, 305 patients (281 men and 24 women) underwent AAA repair with use of endovascular techniques. Outcomes measured included perioperative mortality, percentage of procedures aborted or converted to open abdominal AAA repair, deployment success rate, angiographic success rate, major complication rate, and percentage of patients with endoleaks. RESULTS: Patients of both genders were comparable with respect to mean age (74.4 in men vs 75.9 in women; NS). According to the Society for Vascular Surgery/International Society of Cardiovascular Surgery risk stratification method, men and women were also comparable in age risk score (0.60 vs 0.67; NS), pulmonary risk score (0.50 vs 0.83; NS), and renal risk score (0.28 vs 0.17; NS). However, the cardiac risk score was higher in men (1.31 vs 0.80; P <.05) and maximum AAA diameter was greater in men (57.0 mm vs 52.1 mm; P <.01). Eight perioperative deaths (2.6%) occurred (2.8% of men, 0% of women; NS). Proportionately more procedures were aborted in women than men: four (16.7%) versus six (2.1%; P <.01). Conversion to open repair occurred in four men (1.4%) and no women (NS). Deployment success was achieved in 96.4% of men and 83.3% of women (P <.01). Angiographic success was achieved in 84.1% of men and 80% of women (NS). Of 46 major complications, 42 (14.9%) occurred in 281 men and four (16.7%) occurred in 24 women (NS). Sixty-seven patients had endoleaks: 60 were men (22.1%) and seven were women (35%; NS). CONCLUSIONS: There was no difference between men and women with respect to perioperative mortality and major complication rates. These findings indicate that being a woman does not adversely influence the outcome of endovascular AAA repair. However, women had a higher rate of aborted procedures. Precise preoperative evaluation may help reduce this problem in women.

Detection of isolated hook fractures 36 months after implantation of the Ancure endograft: a cautionary note.

Two cases of delayed (36-month) Ancure hook fracture are reported in patients who experienced a decrease in aneurysm size and no evidence of endoleak. Both devices used redesigned hooks and are otherwise identical to those devices currently used in clinical practice. Notably, hook fractures were not visualized on all abdominal radiographic views, nor were they noted on the final "institutional" report by the reviewing radiologist. Careful clinical follow-up with multiple-view abdominal radiographs remains essential for all patients treated with an endovascular graft, with particular attention directed to the integrity of the metal components. The broader clinical significance of this observation with respect to the Ancure endograft remains to be defined.