Phase I trial on the safety of topical rhVEGF on chronic neuropathic diabetic foot ulcers

OBJECTIVE

To assess the safety/tolerability and perform a preliminary efficacy evaluation of a multiple-dosing regimen of recombinant human vascular endothelial growth factor (VEGF165 or rhVEGF; telbermin) applied topically to chronic diabetic neuropathic foot ulcers.

METHOD

Subjects with type 1 or 2 diabetes mellitus were randomised to receive either topical applied telbermin (72 microg/cm2) (n=29) or placebo (n=26) treatment to the foot ulcer surface in conjunction with standard ulcer care. Subjects received treatment every 48 hours (maximum three doses per week) for up to six weeks. Weekly 35mm photography, quantitative planimetry and physical examinations documented the ulcer appearance, surface area and stage. Safety endpoints included incidence of clinically significant hypotension, adverse events and ulcer infection. Exploratory efficacy endpoints included percentage reduction in total ulcer surface area, incidence of complete ulcer healing and time to complete ulcer healing.

RESULTS

Incidence of adverse events was comparable in the two treatment groups. None of the adverse events were attributed to study drug, and no hypotension was observed as a result of telbermin treatment. Occurrence of infected study ulcers appeared to be balanced between the treatment groups. Positive trends suggestive of potential signals of biological activity were observed for incidence of complete ulcer healing (41.4% telbermin versus 26.9% placebo at day 43 [P=0.39]) and time to complete ulcer healing (25th percentile of 32.5 days telbermin versus 43.0 days placebo [log-rank P=0.13]).

CONCLUSION

The topical application of telbermin 72 microg/cm2 three times a week for up to six weeks appeared to be well tolerated. Further studies are required to characterise the safety/efficacy of telbermin more completely.

Alteplase and tenecteplase: applications in the peripheral circulation

Alteplase (t-PA), a recombinant analogue of human tissue plasminogen activator, became the first genetically engineered thrombolytic approved by the Food and Drug Administration in 1987 for acute myocardial infarction (AMI). In addition to AMI, alteplase is currently approved for the treatment of acute ischemic stroke and pulmonary embolism, and we anticipate approval for catheter clearance in late 2001 in a 2-mg vial configuration. With the withdrawal of human neonatal kidney cell-derived urokinase, alteplase has become an alternative agent in peripheral vascular applications. Because few interventionalists had prior experience with the handling and dosage of alteplase, the Advisory Panel to the Society of Cardiovascular and Interventional Radiology established practice guidelines for use in noncoronary applications. Emerging clinical experience with contemporary dosing regimens shows a safety and efficacy profile similar to urokinase but with significantly reduced drug costs. Tenecteplase (TNK) is a genetically modified version of alteplase. TNK is the only plasminogen activator available that has shown a significantly enhanced safety profile versus alteplase in AMI. Approved for a 5-second, single-bolus injection in AMI, TNK possesses a longer half-life, increased resistance to plasminogen activator inhibitor, and improved fibrin specificity compared with alteplase. Because of its enhanced safety profile, TNK may be a desirable agent for peripheral vascular applications. Initial clinical studies with TNK in acute arterial and venous disease are ongoing. This article outlines the Advisory Panel guidelines for using alteplase and highlights features of tenecteplase.

Transcatheter interventions for the treatment of peripheral atherosclerotic lesions: part I

Transcatheter endovascular procedures are increasingly used to treat symptomatic peripheral atherosclerosis. This two-part review identifies the existing evidence supportive of the application of transcatheter treatments for peripheral atherosclerotic lesions. The first part addresses the treatment of obstructive lesions that cause limb claudication and critical ischemia, renovascular hypertension and azotemia, and mesenteric ischemia. Studies were identified via a search of MEDLINE (January 1993 through April 1999) and reference lists of identified articles. When multicenter prospective randomized trials or other high-quality studies were unavailable, a preference was given to studies with at least 50 patients per treated group and a minimum mean follow-up duration of 6 months. Data presented in tables are proportionally weighted averages from included studies. For each application, the authors assessed the quality of evidence (QOE; efficacy, safety, and, where available, cost-effectiveness) and made recommendations with appropriate caveats. There is higher QOE supporting the more established treatments such as lower limb percutaneous transluminal angioplasty (PTA) with stent placement and thrombolysis. Treatments such as renal artery PTA and stent placement and mesenteric and brachiocephalic PTA are in wide use, but high QOE supporting general application is lacking. Blanket recommendations based on established efficacy and cost-effectiveness cannot be made. However, the use of transcatheter therapies can be supported in specific circumstances based on an expected reduction in procedure-related morbidity and/or mortality rates. It is hoped that the identification of deficiencies in the literature will inform and inspire critically needed research in this area.

Surgical intervention is not required for all patients with subclavian vein thrombosis

PURPOSE

The role of thoracic outlet decompression in the treatment of primary axillary-subclavian vein thrombosis remains controversial. The timing and indications for surgery are not well defined, and thoracic outlet procedures may be associated with infrequent, but significant, morbidity. We examined the outcomes of patients treated with or without surgery after the results of initial thrombolytic therapy and a short period of outpatient anticoagulation.

METHODS

Patients suspected of having a primary deep venous thrombosis underwent an urgent color-flow venous duplex ultrasound scan, followed by a venogram and catheter-directed thrombolysis. They were then converted from heparin to outpatient warfarin. Patients who remained asymptomatic received anticoagulants for 3 months. Patients who, at 4 weeks, had persistent symptoms of venous hypertension and positional obstruction of the subclavian vein, venous collaterals, or both demonstrated by means of venogram underwent thoracic outlet decompression and postoperative anticoagulation for 1 month.

RESULTS

Twenty-two patients were treated between June 1996 and June 1999. Of the 18 patients who received catheter-directed thrombolysis, complete patency was achieved in eight patients (44%), and partial patency was achieved in the remaining 10 patients (56%). Nine of 22 patients (41%) did not require surgery, and the remaining 13 patients underwent thoracic outlet decompression through a supraclavicular approach with scalenectomy, first-rib resection, and venolysis. Recurrent thrombosis developed in only one patient during the immediate period of anticoagulation. Eleven of 13 patients (85%) treated with surgery and eight of nine patients (89%) treated without surgery sustained durable relief of their symptoms and a return to their baseline level of physical activity. All patients who underwent surgery maintained their venous patency on follow-up duplex scanning imaging.

CONCLUSION

Not all patients with primary axillary-subclavian vein thrombosis require surgical intervention. A period of observation while patients are receiving oral anticoagulation for at least 1 month allows the selection of patients who will do well with nonoperative therapy. Patients with persistent symptoms and venous obstruction should be offered thoracic outlet decompression. Chronic anticoagulation is not required in these patients.

Endovascular management of iliac vein compression (May-Thurner) syndrome

PURPOSE

To evaluate the feasibility of endovascular techniques in treating venous outflow obstruction resulting from compression of the iliac vein by the iliac artery of the left lower extremity (May-Thurner syndrome).

MATERIALS AND METHODS

A retrospective analysis of 39 patients (29 women, 10 men; median age, 46 years) with iliac vein compression syndrome (IVCS) was performed. Nineteen patients presented with acute deep vein thrombosis (DVT) and 20 patients presented with chronic symptoms. All patients presented with leg edema or pain. In the acute group, patients were treated with catheter-directed thrombolysis (120,000-180,000 IU urokinase/h) and angioplasty followed by stent placement. In the chronic group, patients were treated with use of angioplasty and stent placement alone (n = 8), or in combination with thrombolysis (n = 12). Patients were then followed-up with duplex ultrasound and a quality-of-life assessment.

RESULTS

Initial technical success was achieved in 34 of 39 patients (87%). The overall patency rate at 1 year was 79%. Symptomatically, 85% of patients were completely or partially improved compared with findings before treatment. Thirty-five of 39 patients received stents. The 1-year patency rate for patients with acute symptoms who received stents was 91.6%; for patients with chronic symptoms who received stents, the 1-year patency rate was 93.9%. Five technical failures occurred. Major complications included acute iliac vein rethrombosis (< 24 hours) requiring reintervention (n = 2). Minor complications included perisheath hematomas (n = 4) and minor bleeding (n = 1). There were no deaths, pulmonary embolus, cerebral hemorrhage, or major bleeding complications.

CONCLUSION

Endovascular reconstruction of occluded iliac veins secondary to IVCS (May-Thurner) appears to be safe and effective.

Stent-graft therapy for subclavian artery aneurysms and fistulas: single-center mid-term results

PURPOSE

To evaluate the potential of covered stents to replace surgery in the treatment of subclavian artery aneurysms and traumatic injuries.

MATERIALS AND METHODS

Nine patients (five men, four women; age range, 20-83 years; mean, 54 years) with subclavian artery aneurysms (n = 5) or fistulas (n = 4) were treated with stent-grafts. All devices used were custom-made, consisting of polytetrafluoroethylene (PTFE)-covered Palmaz (n = 5), Wallstent (n = 2), Z stents (n = 8), or a polyester-covered Z stent (n = 1). One patient was lost to follow-up after 2 months. All others were followed up with clinical evaluation, computed tomography (CT), and/or ultrasound.

RESULTS

All devices were deployed successfully with exclusion of the aneurysms and fistulas. There were two procedure-related complications (22%), consisting of groin pseudoaneurysms requiring surgical repair 3 and 9 days after the procedure. One of those patients required additional oral antibiotic therapy for a postsurgical groin wound infection. One patient developed a stenosis at 12 months, which required angioplasty. The stent-graft thrombosed in one patient because of a kink 2 months after placement, which was successfully treated by thrombolysis and placement of a Wallstent. The primary and secondary patencies are 89% and 100%, respectively, after a mean follow-up of 29 months (2-66 mo).

CONCLUSION

Mid-term results of stent-graft therapy of subclavian artery aneurysms and fistulas are encouraging, with low morbidity and excellent clinical outcome.

Internal iliac artery embolization in the stent-graft treatment of aortoiliac aneurysms: analysis of outcomes and complications

PURPOSE

To analyze the complications of internal iliac artery (IIA) embolization in conjunction with stent-graft treatment of aortoiliac aneurysms.

MATERIALS AND METHODS

Seventy-one patients with aortoiliac (n = 47) or iliac (n = 24) aneurysms were treated with endoluminal placement of stent-grafts. Thirty-two patients (31 men, one woman; mean age, 73 years; range, 56-88 years) had embolization or occlusion of one (n = 27) or both (n = 5) IIAs. Status of the IIAs and the collateral circulation was assessed by retrospective review of angiographic images. Follow-up consisted of a standardized patient questionnaire and review of radiologic and medical records.

RESULTS

The mean follow-up time was 35 months (range, 5-64 months). Eleven of the 47 patients with abdominal aortic aneurysms (AAA) (23%) and 19 of the 24 patients with iliac aneurysms (79%) required IIA embolization. One patient with AAA and another with iliac aneurysm had unintentional occlusion of an IIA by extension of the stent-graft over their origins. A total of seven patients had bilateral occlusion of the IIAs after the procedure. Additionally, the inferior mesenteric arteries (IMAs) of two other patients with AAA were also embolized. In six patients, all three vessels were occluded after placement of the stent-grafts. Symptoms were reported in nine of the 20 (45%) patients with iliac aneurysms and in three of the 12 (25%) patients with AAA. Symptoms consisted of buttock claudication (nine of 32, 28%), new sexual dysfunction (two of 16, 12%), and transient urinary retention (3%). Seven of the claudicants had resolution of symptoms after a mean interval of 14 months (range, 1-36 months). There were no instances of bowel ischemia, neurologic sequelae, or buttock necrosis related to these procedures.

CONCLUSION

Embolization of the IIA is associated with symptoms in a significant number of patients. While symptoms are transient in most patients, they can be problematic. Efforts should be made to preserve the pelvic circulation if possible.

Aortic aneurysmal disease: assessment of stent-graft treatment-CT versus conventional angiography

PURPOSE

To compare computed tomographic (CT) angiography and conventional angiography for determining the success of endoluminal stent-graft treatment of aortic aneurysms.

MATERIALS AND METHODS

Forty patients underwent conventional angiography and CT angiography following treatment of aortoiliac aneurysms with endoluminal stent-grafts. Six additional sets of conventional angiographic-CT angiographic examinations were performed in five patients after placement of additional stent-grafts or coil embolization to treat perigraft leakage. Three faculty CT radiologists who were blinded to patient clinical data and outcome independently interpreted the CT angiograms, and three faculty angiographers, who were not involved in the stent-graft deployment, interpreted the conventional angiograms. Images were assessed for the presence of postdeployment complications. A reference standard was developed by experienced radiologists using all available images and clinical data. Sensitivities, specificities, and kappa values were calculated.

RESULTS

Perigraft leakage was the most commonly identified complication. Twenty perigraft leaks were detected in the results of 46 examinations. Sensitivities and specificities for detecting perigraft leakage were 63% and 77% for conventional angiography and 92% and 90% for CT angiography, respectively. The kappa value was 0. 41 for conventional angiography and 0.81 for CT angiography.

CONCLUSION

CT angiography is the preferred method for establishing the presence of perigraft leakage following treatment of aortoiliac aneurysms with stent-grafts.

Thrombolytic therapy with use of alteplase (rt-PA) in peripheral arterial occlusive disease: review of the clinical literature. The Advisory Panel

PURPOSE

The clinical literature describing the use of alteplase in the treatment of peripheral arterial occlusive (PAO) disease is reviewed.

MATERIALS AND METHODS

The literature database was acquired by a MEDLINE search using the Boolean keyword string: tissue plasminogen activator and/or rt-PA and peripheral not animal. A review was performed to identify the dose range of alteplase, technique of infusion, use of anticoagulation, clinical success rates, and risk of complications.

RESULTS

Forty-six clinical studies were identified. There are few prospective, randomized clinical trials and a lack of standardized protocols and endpoints. Use of catheter-directed infusions of recombinant tissue plasminogen activator (rt-PA) may be beneficial versus surgery in the initial management of acute limb ischemia (< 14 days) and in reducing the magnitude of subsequent surgical or percutaneous revascularization. For patients with chronic limb ischemia (> 14 days), irreversible acute limb ischemia, or advanced diabetic arteriopathy, catheter-directed infusion of rt-PA or other plasminogen activators may be unsuitable. The risk of adverse bleeding appears related to the overall dose and duration of infusion. These risks appear similar to those of urokinase. The role of heparin in increasing adverse bleeding during rt-PA therapy is unclear.

CONCLUSIONS

There is no generally accepted dose or technique for administering catheter-directed thrombolysis using alteplase; however, several studies have demonstrated its clinical safety and efficacy. Formal studies will be required to determine the optimal dose, technique of infusion, the role of anticoagulation, and complication rates when alteplase is used for PAO disease.

True-lumen collapse in aortic dissection: part II. Evaluation of treatment methods in phantoms with pulsatile flow

PURPOSE

To discover and evaluate the effective treatment methods to prevent or relieve true-lumen collapse in models of aortic dissection.

MATERIALS AND METHODS

Two phantoms were built to simulate type B aortic dissection. After true-lumen collapse was induced, experiments were conducted to evaluate the effectiveness of clinically relevant variables in relieving the collapse. Variables included entry-tear size, branch-vessel flow distribution, distal reentry communication between the true and false limbs, aortic fenestrations, and pump output. To test the effect of closing the entry tear, a stent-graft was deployed over the entry tear under physiologic conditions in a mock-flow loop. The difference in the effect of each variable on the prevention and relief of true-lumen collapse was also investigated.

RESULTS

It was more difficult to relieve true-lumen collapse than it was to prevent it. Placement of a stent-graft over the entry tear was the most effective method of relieving true-lumen collapse. Less-effective procedures included opening a false-lumen outflow branch and opening the distal reentry branch. Opening the fenestration-branch loops, meant to simulate the creation of artificial fenestrations in the intimal flap, did not relieve true-lumen collapse.

CONCLUSION

The definitive treatment for true-lumen collapse in aortic dissection is direct repair of the entry tear to decrease false-lumen inflow. Otherwise, increasing the false-lumen outflow and/or creating distal fenestrations between the true and false lumina distal to the level of the compromised aortic branch are less-effective alternatives.

Chronically occluded inferior venae cavae: endovascular treatment

PURPOSE

To report the results of endoluminal recanalization and stent placement in patients with chronic occlusions of the inferior vena cava (IVC).

MATERIALS AND METHODS

Seventeen consecutive patients (12 male, five female patients; mean age, 40.6 years; age range, 15-77 years) with chronic IVC occlusions were treated during a 6-year period. The mean duration of symptoms was 32 months. Underlying active malignancy was the cause of occlusion in four patients. Five patients with superimposed acute thrombus underwent catheter-directed thrombolysis prior to IVC recanalization. Clinical patency was defined as absence or improvement of symptoms. Clinical follow-up was supplemented with ultrasonography, vena cavography, or both in 10 patients.

RESULTS

Technical success was achieved in 15 (88%) patients. Additional thrombolytic therapy and stent placement was needed in two patients to maintain patency at 4 and 6 months after the procedure. Twelve patients had IVCs that remained patent after a mean follow-up of 19 months for a primary patency rate of 80%. The primary assisted patency rate was 87% (13 of 15). There were four deaths owing to underlying disease 6-21 months after the procedures. There were no procedure-related complications.

CONCLUSION

Endoluminal recanalization and stent placement in chronically occluded IVCs has a good intermediate-term outcome and should be considered in patients who have symptoms and who often do not have adequate alternative therapy.

True-lumen collapse in aortic dissection: part I. Evaluation of causative factors in phantoms with pulsatile flow

PURPOSE

To investigate the causative factors in true-lumen collapse in a model of aortic dissection.

MATERIALS AND METHODS

Phantoms with an aortic arch, true and false lumina with abdominal branch vessels, and a distal bifurcation were used to model a Stanford type B aortic dissection. The effects of anatomic factors (entry-tear size, branch-vessel flow distribution, fenestrations, distal reentry communication) and physiologic factors (peripheral resistance in the branch vessels, pump output and rate, vascular compliance) on true-lumen collapse were investigated. The morphology of the true lumen was observed. Branch pressures and flow rates were measured.

RESULTS

True-lumen collapse was induced and was exacerbated by an increase in the size of the entry tear, a decrease in the false-lumen outflow caused by occluding the false-lumen branch vessels, and an increase in the true-lumen outflow caused by lowering the peripheral resistance in true-lumen branch vessels. Two kinds of true-lumen collapse depended on pump output. With low pump output and low outflow resistance from the true lumen, the true lumen collapsed. With high pump output and low inflow resistance in the false lumen, the true lumen was compressed. Distal reentry communication between the true and false limbs was more effective than aortic fenestrations in preventing true-lumen collapse.

CONCLUSION

True-lumen collapse in this dissection model strongly depends on the difference in the ratios of inflow capacity to outflow capacity in the true and false lumina. Both anatomic and physiologic factors can affect true-lumen collapse.

Diagnostic yield of MR-guided liver biopsies compared with CT- and US-guided liver biopsies

PURPOSE

To compare diagnostic yield and complication rates of magnetic resonance (MR)-guided versus computed tomography (CT)- and ultrasound (US)-guided liver biopsies.

MATERIALS AND METHODS

MR-, CT-, and US-guided liver biopsies performed between 9/96 and 9/98 were compared. Sixty patients (21 men and 39 women, mean age 60 years) underwent MR-guided biopsy of liver lesions. Thirty patients (16 men and 14 women, mean age 59 years) underwent CT-guided biopsy. Eighteen patients (seven men and 11 women, mean age 50 years) underwent US-guided biopsy. MR procedures were performed in an open-configuration 0.5-T Signa SP MR unit. Lesion localization used standard T1 and T2 sequences, whereas biopsies were performed with multiplanar spoiled gradient recalled echo and fast gradient recalled echo sequences. A coaxial system with an MR-compatible 18-gauge stabilizing needle and a 21-gauge aspiration needle was used to obtain all samples. In CT and US procedures, a 19-gauge stabilizing needle and a 21-gauge aspiration or a 20-gauge core biopsy needle were used. A cytotechnologist was present to determine the adequacy of samples.

RESULTS

MR had a diagnostic yield of 61%. CT and US had diagnostic yields of 67% and 61%, respectively. No serious complications were reported for MR and US procedures. Two CT biopsies resulted in postprocedural hemorrhage. One patient required surgical exploration and died.

CONCLUSIONS

MR-guided biopsy of liver lesions with use of a 0.5-T open-configuration magnet is safe and accurate when compared with CT and US. No statistical difference was observed between the diagnostic yield of biopsies performed with MR, CT, and US guidance. MR enabled biopsy of a number of lesions in the hepatic dome and lesions with low contrast, which would normally be difficult to sample safely with use of CT or US.

Endovascular treatment of hepatic venous outflow obstruction after piggyback technique liver transplantation

BACKGROUND

The piggyback technique of orthotopic liver transplantation is an attractive alternative that preserves the recipient inferior vena cava and allows uninterrupted venous blood return during the anhepatic phase. As with other transplantation techniques, the vascular anastomoses required by the piggyback technique can develop strictures.

METHODS

Review of records of 264 piggyback transplantations revealed two cases of delayed-onset hepatic venous obstruction from anastomotic strictures. Both patients also had symptoms of inferior vena cava obstruction, with azotemia and lower extremity edema. Both patients were treated percutaneously with balloon-expandable stents.

RESULTS

Rapid, dramatic resolution of symptoms was achieved in both patients. Patients remain completely asymptomatic at 39 and 3 months of follow-up.

CONCLUSIONS

Hepatic venous anastomotic strictures in recipients of piggyback technique transplants are a very uncommon complication. They may be easily and effectively treated by minimally invasive endovascular intervention.

Management of misplaced or migrated endovascular stents

PURPOSE

To report experience with techniques for management of misplaced or migrated endovascular stents.

MATERIALS AND METHODS

During a 5-year period, percutaneous management of 27 misplaced or migrated endovascular stents (16 Palmaz, 11 Wallstents) in 25 patients was attempted. The 17 venous and 10 arterial stents were rescued from the aorta (n = 9), inferior vena cava (IVC) (n = 4), transjugular intrahepatic portosystemic shunt/IVC (n = 2), right atrium (n = 3), right ventricle (n = 2), pulmonary artery (n = 2), iliac vein (n = 2), iliac artery (n = 1), superior vena cava (n = 1), and superior mesenteric vein (n = 1).

RESULTS

Stent management was successful in 26 of 27 cases (96%). Eleven stents were removed percutaneously, two were repositioned and removed with a minor surgical procedure, and 13 were repositioned and deployed in a stable alternate location. The only complication was the development of tricuspid insufficiency in the single case in which the procedure failed (4% complication rate). This patient's stent was eventually surgically removed from the right ventricle.

CONCLUSION

Misplaced or migrated endovascular Palmaz and Wallstents can be effectively managed with few complications by using a variety of percutaneous techniques.

Descending thoracic aortic aneurysm: thoracic CT findings after endovascular stent-graft placement

PURPOSE

To evaluate the usefulness of thoracic computed tomography (CT) after placement of an endovascular stent-graft for the treatment of descending thoracic aortic aneurysm.

MATERIALS AND METHODS

From 1992 to 1996, 85 patients with thoracic aortic aneurysm underwent stent-graft placement. In 63 patients, thoracic CT scans were obtained both before and within 10 days after placement. The CT findings were retrospectively studied, and their clinical effect analyzed. In 20 of 63 patients, long-term follow-up CT findings were also evaluated.

RESULTS

After stent-graft placement in the 63 patients, CT demonstrated an increase in pleural effusion in 46 (73%), periaortic changes in 21 (33%), perigraft leak in 13 (21%), atelectasis in six (10%), mural thrombus within the stent-graft in two (3%), and new aortic dissection in one (2%). The mean maximum diameter of the aneurysm was 58.8 mm before and 60.0 mm after stent-graft insertion. Sixty-two (98%) patients were successfully treated until discharge. Interventional procedures were performed to eliminate the leakage into the aneurysm sac in 10 patients with perigraft flow depicted at CT. Other complications were managed conservatively.

CONCLUSION

Thoracic CT is useful in the treatment of patients after stent-graft insertion for the management of descending thoracic aortic aneurysm.

Recurrent TIPS failure associated with biliary fistulae: treatment with PTFE-covered stents

PURPOSE

To evaluate the efficacy of covered stents for the treatment of transjugular intrahepatic portosystemic shunt (TIPS) obstruction in human subjects with identified or suspected biliary fistulae.

METHODS

Five patients were treated for early failure of TIPS revisions. All had mid-shunt thrombus, and four of these had demonstrable biliary fistulae. Three patients also propagated thrombus into the native portal venous system and required thrombolysis. TIPS were revised in four patients using a custom-made polytetrafluoroethylene (PTFE)-covered Wallstent, and in one patient using a custom-made PTFE-covered Gianturco Z-stent.

RESULTS

All identified biliary fistulae were successfully sealed. All five patients maintained patency and function of the TIPS during follow-up ranging from 2 days to 21 months (mean 8.4 months). No patient has required additional revision. Thrombosis of the native portal venous system was treated with partial success by mechanical thrombolysis.

CONCLUSION

Early and recurrent failure of TIPS with mid-shunt thrombosis, which may be associated with biliary fistulae, can be successfully treated using covered stents. Stent-graft revision appears to be safe, effective, and potentially durable.

Percutaneous balloon fenestration and stenting for life-threatening ischemic complications in patients with acute aortic dissection

OBJECTIVES

Acute aortic dissection frequently causes life-threatening ischemia of end-organs, historically associated with mortality exceeding 60%. Reperfusion with the use of interventional radiologic methods has evolved as a promising treatment. We report results of our initial 6 years of experience with percutaneous balloon fenestration of the intimal flap and endovascular stenting.

METHODS

Forty patients (32 male and 8 female) with a median age of 53 years (range 16-86 years) underwent percutaneous treatment for peripheral ischemic complications of 10 type A and 30 type B acute aortic dissections since 1991. Twenty patients had ischemia of multiple organ systems. Thirty patients had renal, 22 had leg, 18 had mesenteric, and 1 had arm ischemia.

RESULTS

Fourteen patients were treated with stenting of either the true or false lumen combined with balloon fenestration of the intimal flap, 24 with stenting alone, and 2 with fenestration alone. Successful revascularization was achieved in 93% +/- 4% (+/-70% confidence levels) of patients (37/40). Nine patients had procedure-related complications. The 30-day mortality rate was 25% +/- 7% (10/40), often related to irreversible ischemia of intra-abdominal organs that was present before the procedure. Of the remaining 30 patients, 5 have died and the remaining 25 continue to have relief of ischemic symptoms at a mean follow-up of 29 months.

CONCLUSION

Percutaneous balloon fenestration of the intimal flap and endovascular stenting is an effective treatment for life-threatening ischemic complications of acute aortic dissection.

Thoracic aortic aneurysm repair with an endovascular stent graft: the "first generation"

OBJECTIVE

The feasibility and efficacy trial of an endovascular stent-grafting system for the treatment of aneurysms of the descending thoracic aorta was investigated.

METHODS

After Institutional Review Board approval, 103 patients (mean age 69 years) underwent stent graft repair of a descending thoracic aortic aneurysm between July 1992 and November 1997. The stent graft was fabricated using self-expanding "Z" stents covered by a woven Dacron tube graft. Follow-up, which averaged 22 months, was 100% complete. Simultaneous open abdominal aortic aneurysm repair was performed in 19 patients.

RESULTS

Complete aneurysm thrombosis was achieved in 86 patients (83%). Early mortality, defined as a death during the same hospitalization or in less than 30 days, was 9 +/- 3%, and was significantly associated with preoperative cerebrovascular accident (CVA) or myocardial infarction. Major perioperative morbidity occurred in 31 patients, and included paraplegia in 3, CVA in 7, and respiratory insufficiency in 12 patients each. Actuarial survival was 81 +/- 4% at 1 year, and 73 +/- 5% at 2 years. Treatment failure (including all late, sudden, unexplained deaths) occurred in 38 patients, and only 53 +/- 10% of patients were free of treatment failure at 3.7 years. Five patients required late operative therapy for endoleaks associated with aneurysm enlargement.

CONCLUSIONS

Satisfactory results were achieved using this "first-generation" homemade stent graft device. Mortality and morbidity occurred frequently, but may have been associated with the high-risk character of this patient population. Medium-term results were acceptable, but continued aortic enlargement, with the late development of endoleaks, is a significant concern. Second-generation devices with commercial development, coupled with this initial experience, should allow improved clinical results in the future. Longer term follow-up is still necessary to fully define the efficacy of this endovascular approach.

Endovascular stent-graft placement for the treatment of acute aortic dissection

BACKGROUND

The standard treatment for acute aortic dissection is either surgical or medical therapy, depending on the morphologic features of the lesion and any associated complications. Irrespective of the form of treatment, the associated mortality and morbidity are considerable.

METHODS

We studied the placement of endovascular stent-grafts across the primary entry tear for the management of acute aortic dissection originating in the descending thoracic aorta. We evaluated the feasibility, safety, and effectiveness of transluminal stent-graft placement over the entry tear in 4 patients with acute type A aortic dissections (which involve the ascending aorta) and 15 patients with acute type B aortic dissections (which are confined to the descending aorta). Dissections involved aortic branches in 14 of the 19 patients (74 percent), and symptomatic compromise of multiple branch vessels was observed in 7 patients (37 percent). The stent-grafts were made of self-expanding stainless-steel covered with woven polyester or polytetrafluoroethylene material.

RESULTS

Placement of endovascular stent-grafts across the primary entry tears was technically successful in all 19 patients. Complete thrombosis of the thoracic aortic false lumen was achieved in 15 patients (79 percent), and partial thrombosis was achieved in 4 (21 percent). Revascularization of ischemic branch vessels, with subsequent relief of corresponding symptoms, occurred in 76 percent of the obstructed branches. Three of the 19 patients died within 30 days, for an early mortality rate of 16 percent (95 percent confidence interval, 0 to 32 percent). There were no deaths and no instances of aneurysm or aortic rupture during the subsequent average follow-up period of 13 months.

CONCLUSIONS

These initial results suggest that stent-graft coverage of the primary entry tear may be a promising new treatment for selected patients with acute aortic dissection. This technique requires further evaluation, however, to assess its therapeutic potential fully.

1999 Gary J. Becker Young Investigator Award. MR-guided transjugular portosystemic shunt placement in a swine model

PURPOSE

To evaluate the performance of portal venous puncture with use of magnetic resonance (MR) guidance, and to place a transjugular intrahepatic portosystemic shunt (TIPS) in a swine model.

MATERIALS AND METHODS

A study of 12 swine was performed to evaluate the ability of interventional MR imaging to guide portal vein puncture and TIPS placement. Six swine had catheters placed in the right hepatic vein under C-arm fluoroscopy. A nitinol guide wire was left in the vein and the animals were then moved into an open configuration MR imaging unit. A TIPS needle set was used to puncture the portal vein using MR fluoroscopy. The animals were transferred to the C-arm, and venography confirmed portal vein puncture. A follow-up study was performed in six additional swine to place a TIPS using only MR imaging guidance. MR tracking was used to advance a catheter from the right atrium into the inferior vena cava. Puncture of the portal vein was performed and a nitinol stent was placed, bridging the hepatic parenchyma. MR venogram confirmed placement.

RESULTS

Successful portal vein puncture was achieved in all animals. The number of punctures required decreased from 12 in the first animal to a single puncture in the last eight swine. A stent was successfully placed across the hepatic tract in all six swine.

CONCLUSIONS

Real-time MR imaging proved to be a feasible method to guide portal vein puncture and TIPS placement in pigs.

The "first generation" of endovascular stent-grafts for patients with aneurysms of the descending thoracic aorta

OBJECTIVE

Our goal was to determine whether endovascular stent-grafting is feasible and effective for patients with aneurysms of the descending thoracic aorta.

METHODS

Starting in July 1992, we conducted a prospective, uncontrolled clinical trial in 103 patients (mean age 69 years [range 34-89 years]) who underwent endovascular treatment of aneurysms of the descending thoracic aorta using a custom-fabricated, self-expanding stent-graft device. Follow-up was 100% complete and averaged 22 months. Sixty-two patients (60%) were judged not to be reasonable candidates for a conventional "open" surgical procedure.

RESULTS

Complete thrombosis of the aneurysm was ultimately achieved in 86 (83%) patients. The early mortality rate was 9% +/- 3% (+/- 70% CL). Multivariable analysis revealed that myocardial infarction or stroke was linked with a higher likelihood of early death (P = .001). Early serious complications included paraplegia in 3% +/- 2% and stroke in 7% +/- 3%. Actuarial survival estimates at 1 year and 2 years were 81% +/- 4% and 73% +/- 5% (+/- 1 SE), respectively; being judged not to be a surgical candidate portended a higher probability of death (P = .003). According to the intent-to-treat principle, "treatment failure" (including all late sudden unexplained deaths) occurred in 38 patients; 53% +/- 10% of patients were free from treatment failure at 3.7 years. Stent-graft related complications occurred commonly and were linked with several anatomic, technical, and patient-related risk factors.

CONCLUSIONS

This 5-year clinical trial involving use of a "first generation" device indicates that endovascular stent-grafting of descending thoracic aortic aneurysms is feasible with acceptable medium-term results. More refined, commercially developed devices available today offer less traumatic and more precise stent-graft deployment; these major technical advantages, coupled with important lessons we have learned over time and better patient selection, should be associated with more salutary clinical results in the future.

Superior vena cava syndrome after heart transplantation: percutaneous treatment of a complication of bicaval anastomoses

OBJECTIVES

Our objectives were (1) to investigate the incidence and cause of symptomatic superior vena caval anastomotic stenosis and central venous thrombosis in patients receiving heart or heart-lung transplantation and (2) to explore percutaneous methods of thrombolysis and endoluminal intervention to treat these complications.

METHODS

Review of 1016 cases revealed three cases of superior vena cava syndrome. Anatomy, surgical technique, and medical risk factors were examined. Percutaneous treatments, including urokinase thrombolysis, mechanical thrombolysis, balloon angioplasty, and stent placement, were attempted.

RESULTS

All three of these patients underwent transplantation by means of the bicaval anastomotic technique. In addition, the diameters of the donor and recipient cavae were grossly mismatched in all three. Stenoses in all three patients were successfully treated percutaneously with balloon angioplasty and stent placement. Treatment of the accompanying large-volume thrombosis was problematic in these patients, and two had hemorrhagic complications of urokinase thrombolysis. A mechanical thrombolysis device was used successfully in the third patient.

CONCLUSIONS

Anastomotic stricture and central venous thrombosis is an uncommon complication of the bicaval anastomotic technique of heart and heart-lung transplantation. Discrepancy between donor and recipient caval diameters appears to be the major risk factor. Endoluminal thrombolysis and stenting provides rapid and enduring relief of symptoms and precludes repeat sternotomy, cardiopulmonary bypass, and general anesthesia.

Percutaneous creation of acute type-B aortic dissection: an experimental model for endoluminal therapy

PURPOSE

To evaluate the feasibility of a percutaneously created type-B aortic dissection as an experimental model for percutaneous therapy. This model was used to evaluate the hemodynamic effects of single-balloon fenestration of the intimal flap.

MATERIALS AND METHODS

Acute type-B dissections were created in descending aortae of 15 swine via a femoral (n = 6) or carotid (n = 9) approach. The initial subintimal tear was made with use of a Colapinto needle. The dissections were extended to a predefined position in the aorta. The proximal and distal tears were balloon dilated. The mural flap was balloon fenestrated in six animals, just above the celiac artery. Aortograms were obtained to establish the presence and extent of the dissection. Manometry was performed in both lumina to evaluate the hemodynamics of the dissected aorta and the effects of balloon fenestration in this model. Pathologic specimens were also examined.

RESULTS

Creation of dissection was successful in 11 of 15 animals, with six developing true lumen narrowing (group A). The other five animals (group B) had flow in both lumina without evidence of true lumen narrowing. After the creation of a single-balloon fenestration in the group A swine, the arteriograms revealed no evidence of blood admixture between the true and false lumina, and there was no change in the intravascular pressures. Examination of the explanted aortae showed a more extensive circumferential dissection in group A animals as compared with group B.

CONCLUSION

The percutaneously created acute type-B aortic dissection is a feasible model for experimentation. The hemodynamics of the aorta did not change after single-balloon fenestration in this model.

Thoracic aortic aneurysm repair with endovascular stent-grafts

The purpose of the study was to describe the clinical experience is using endoluminal stent-grafts for the treatment of thoracic aortic aneurysms in high-risk patients. Patients with aneurysms of the descending thoracic aorta who were considered high surgical risks underwent evaluation for endoluminal repair. The prosthesis was constructed from Z stents covered with polyester fabric using dimensions based upon preprocedural computed tomography scans and angiography. Through a femoral arteriotomy or left retroperitoneal flank incision, a 22-24 Fr delivery catheter was inserted and advanced through the aorta to the target site under fluoroscopic guidance in the operating suite. The stent-graft prosthesis was deployed at the site of the aneurysm. 44 patients (36 male, 8 female; mean age 36 years) underwent stent-graft repair for thoracic aneurysms (mean diameter 6.3 cm). The deployment was technically successful in all cases, with complete aneurysm thrombosis in 88%. The 30-day perioperative mortality rate was 6.8% and 35-month actuarial survival was 82%. There were no cases of stent migration, surgical conversion or intraprocedural death. Paraplegia occurred in two patients who underwent simultaneous surgical infrarenal aortic aneurysm repair immediately followed by stent-graft placement for a coexisting thoracic aneurysm. The conclusion was that placement of endoluminal stent-grafts for repair of thoracic aortic aneurysms is technically feasible in high-risk patients in whom conventional surgery is contraindicated. Long-term studies are needed to determine protection against aneurysm rupture and patient survival.

Iliofemoral venous thrombosis treated by catheter-directed thrombolysis, angioplasty, and endoluminal stenting

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Mycotic aneurysms of the thoracic aorta: repair with use of endovascular stent-grafts

PURPOSE

Standard therapy of mycotic aneurysms in the descending aorta consists of thoracotomy and in situ graft placement or extraanatomic bypass. The alternative use of endovascular stent-grafts was evaluated for management of infected aneurysms of the thoracic aorta.

MATERIALS AND METHODS

In a retrospective analysis during a 5-year period, 112 patients underwent stent-graft placement for thoracic aortic aneurysms. Three patients (mean age, 68.6; range, 64-70 years) had mycotic thoracic aneurysms. Stent-grafts were constructed from Z stents covered with polyester fabric and were delivered remotely through a catheter under fluoroscopic guidance.

RESULTS

Complete thrombosis of the mycotic aneurysms was achieved in all patients. One patient required a second separate stent-graft placement procedure because of migration of the initial device; the second patient underwent surgical repair of a ruptured mycotic abdominal aortic aneurysm followed immediately by stent-graft placement for a chronic mycotic thoracic aneurysm; a third patient underwent repair of two infected false aneurysms secondary to complete rupture of a surgical interposition graft. There were no complications of persistent bacteremia despite placement of the stent-graft device at the site of primary infection, reinfection, delayed rupture, paraplegia, distal emboli, or surgical conversion. One patient died of cardiac arrest at 25 months; there were no perioperative deaths (< or = 30 days). The remaining two patients were alive and well at median follow-up of 24 months (range, 4-25 months).

CONCLUSION

Endovascular stent-grafts combined with antibiotic therapy may be an alternative to conventional thoracotomy in managing mycotic aneurysms of the descending thoracic aorta.

Transbronchial Palmaz stent placement for tracheo-bronchial stenosis

PURPOSE

Evaluation of the efficacy of transbronchial Palmaz stent placement in the treatment of tracheo-bronchial narrowing.

MATERIALS AND METHODS

Twelve patients with stenoses of the tracheo-bronchial tree were treated with balloon-expandable Palmaz stents. Etiology was anastomotic stenosis after lung transplantation (n = 3), bronchogenic carcinoma (n = 2), external compression from thoracic aortic aneurysm (n = 2), Mycobacterium tuberculosis (n = 1), esophageal carcinoma (n = 1), after lobectomy (n = 1), after lobectomy and endobronchial radiation (n = 1), and lye ingestion (n = 1). All patients had respiratory symptoms, radiologic findings of persistent atelectasis, or worsening pulmonary function tests. Bronchoscopy was used to delineate the stenosis prior to intervention. With use of fluoroscopic guidance, stents were placed in the mainstem bronchus (n = 11), lower lobe bronchus (n = 5), bronchus intermedius (n = 5), trachea (n = 3), and middle lobe bronchus (n = 1).

RESULTS

Initial technical success was achieved in all patients. Ten of the 12 patients (83%) had improvement of clinical pulmonary signs or symptoms. During follow-up, five patients died. One was lost to follow-up and was presumed dead. The 30-day mortality rate was 17% (two of 12 patients). The two complications were superficial laceration of the bronchial mucosa during balloon dilation in one patient and compression of stents by a thoracic aortic aneurysm in another patient.

CONCLUSION

Initial results suggest that transbronchial Palmaz stent placement is a feasible and effective method of treating tracheo-bronchial stenosis.

Treatment of aortoiliac aneurysms with use of single-piece tapered stent-grafts

PURPOSE

The authors describe their experience with the use of single-piece, tapered stent-grafts for the treatment of abdominal aortic or aortoiliac aneurysms.

MATERIALS AND METHODS

Single-piece, tapered stent-grafts were placed in 15 patients for the treatment of abdominal aortic aneurysms with small distal necks (n = 13), and aortoiliac aneurysms (n = 2). There were 13 men and two women who ranged in age from 59 to 83 years (mean, 71 years). Usual open surgery was considered high risk in all patients because of comorbid medical conditions. The stent-grafts were made of Z stents covered with polytetrafluoroethylene (PTFE). Additional stent-grafts needed to treat perigraft leaks were made of Z stents covered with woven polyester (n = 5), Wallstents covered with PTFE (n = 2), Z stents covered with PTFE (n = 1), and a PTFE-covered Palmaz stent (n = 1). After stent-graft placement, the contralateral iliac artery was occluded by a blocking device composed of either a PTFE-covered Palmaz (n = 1) or Z stent (n = 13), and a femoral-femoral bypass was created.

RESULTS

After placement of the stent-grafts, immediate perigraft leaks were observed in eight patients (53%). These were at the proximal (n = 5) or the distal end (n = 3). All, except one, were treated successfully with additional stent-grafts. The one failure was in a patient who developed aortic rupture after balloon dilation, requiring open surgical repair. Second procedures were required in four patients (27%), including three leaks treated successfully with coil embolization and/or a back-up stent-graft, and one stent-graft migration and thrombosis treated by thrombolysis and placement of an additional stent-graft. One patient died of respiratory failure 23 days after placement of the stent-graft. The mean follow-up was 12 months (range, 4-26 months). On the last follow-up, the aneurysms in the 13 living patients remained thrombosed.

CONCLUSION

Treatment of aortoiliac aneurysms with use of single-piece, tapered stent-grafts is feasible in selected patients. The morbidity and mortality rates compare favorably with those of the open surgical procedures in a high-risk population. Further improvements in the technique and longer follow-up data are needed before this procedure can be recommended for the treatment of all aortoiliac aneurysms.

Superior vena cava syndrome: treatment with catheter-directed thrombolysis and endovascular stent placement

PURPOSE

To evaluate use of catheter-directed thrombolysis and/or endovascular stent placement to treat superior vena cava (SVC) syndrome.

MATERIALS AND METHODS

Fifty-nine consecutive patients with SVC syndrome were studied. The cause was underlying malignancy in 43 and benign disease in 16. All patients underwent bilateral upper-extremity venography. The SVC was occluded in 31 cases and stenosed in 28. Twenty-seven patients underwent catheter-directed thrombolysis; 51 underwent endovascular stent placement. Patency was defined in terms of absence of symptoms and signs of SVC syndrome.

RESULTS

Technical success was achieved in 56 of 59 patients (95%). Among 42 patients with underlying malignancy (mean follow-up, 7.0 months; range, 1-34 months), primary clinical patency was achieved in 33 (79%) and secondary clinical patency was achieved in 39 (93%). Among 13 patients with benign disease (mean follow-up, 17.0 months; range, 1-27 months), primary clinical patency was achieved in 10 (77%) and secondary clinical patency was achieved in 11 (85%). Four patients were lost to follow-up. Periprocedural mortality and morbidity rates were 3% (two of 59 patients) and 10% (six of 59 patients), respectively.

CONCLUSION

Catheter-directed thrombolysis and endovascular stent placement is a safe and effective treatment for SVC syndrome.

Traumatic thoracic aortic aneurysm: treatment with endovascular stent-grafts

PURPOSE

To demonstrate the feasibility and safety of endovascular stent-graft placement for treatment of traumatic aortic aneurysm.

MATERIALS AND METHODS

Ten patients with traumatic aortic aneurysm were treated with endovascular stent-grafts. Three patients had an acute traumatic aneurysm; seven had a chronic aneurysm. Stent-grafts were constructed from modified Z-stents covered with woven polyester or expanded polytetrafluoroethylene graft material and were deployed through a 20-24-F delivery sheath in an exposed artery located remotely from the lesion.

RESULTS

Stent-graft placement and thrombosis of the aneurysmal sac were successful in all patients. Major complications were encountered in three patients after endovascular treatment. One patient had a peri-graft leak; complete thrombosis of the aneurysmal sac was achieved after coil embolization of the leak. Transposition of the left subclavian artery was necessary to relieve left arm ischemia in another patient. In the third patient, stent placement in the left main stem bronchus was needed to relieve left lung atelectasis. All patients were alive and without complications during the follow-up period (mean, 15 months).

CONCLUSION

Transluminal placement of endovascular stent-grafts is a technically feasible method for treatment of traumatic thoracic aortic aneurysm and may be an effective alternative to open-chest surgery.

Acute rupture of the descending thoracic aorta: repair with use of endovascular stent-grafts

PURPOSE

To describe the use of endovascular stent-grafts to treat acute ruptures of the descending thoracic aorta as an alternative to surgery in high-risk patients.

MATERIALS AND METHODS

From July 1992 to August 1996, 95 patients underwent stent-grafting of the descending thoracic aorta for a variety of lesions. Of these, 11 patients with acute (< or = 7 days) rupture from aneurysms (n = 8) or trauma (n = 3) underwent repair with use of endovascular stent-grafts. Rupture was confirmed with preoperative imaging studies and occurred in the mediastinum (n = 9), the pleural space (n = 1), or the lung (n = 1). All patients were considered high surgical risk due to generalized cardiopulmonary disease and/or previous thoracotomies. Stent-grafts were constructed from Z stents covered with polyester fabric and delivered through a catheter under fluoroscopic control from a remote access site.

RESULTS

Stent-graft deployment was successful in all patients. There were no complications of perigraft leak, stent migration, paraplegia, or intraoperative death. Two patients died in the follow-up period: one of ventricular perforation during unrelated thoracic surgery for tumor resection (day 1) and one of cardiac arrest (day 28). All others are alive (mean follow-up, 15.1 months).

CONCLUSION

For acute rupture of the thoracic aorta, endovascular stent-graft repair is technically feasible and may be a therapeutic alternative to a surgical interposition graft in patients considered high risk for conventional thoracotomy. Long-term studies are necessary to determine the role of stent-grafts in preventing future aortic rupture.

Use of a self-expanding vascular occluder for embolization during endovascular aortic aneurysm repair

PURPOSE

Repair of aortic aneurysms with use of stent-graft techniques may require occlusion of large branch vessels to prevent back-bleeding into the excluded aneurysmal sac. The authors describe their experience using a self-expanding vascular occluder (SEVO) to occlude flow in branch arteries during aortic stent-grafting.

PATIENTS AND METHODS

Eighty-four patients (65 men, 19 women; mean age, 64 years) underwent thoracic (n = 72) or abdominal aortic (n = 12) stent-grafting. Aneurysm repair was performed using nonbifurcated Z stents covered with polyester or polytetrafluoroethylene (PTFE) fabric. SEVOs constructed from a Z stent (10-20 mm diameter) and PTFE were deployed through a separate catheter (14-20 F).

RESULTS

Ten of 84 patients required embolization of large branch arteries with use of a SEVO during aortic stent-grafting (thoracic, n = 1; abdominal, n = 9). The SEVO was placed in the common iliac (n = 9) or subclavian artery (n = 1). The mean SEVO diameter was 14.7 mm (range, 10-20 mm). Eight patients undergoing SEVO embolization had immediate thrombosis of the treated artery. One patient required additional embolization with use of conventional coils. No patients had back-bleeding into the aneurysm, device migration, microembolization, or limb ischemia (mean follow-up, 140 days; range, 50-200). All 10 patients had complete thrombosis of the aortic aneurysm.

CONCLUSION

Use of a novel self-expanding vascular occluding device is a safe and effective supplementary technique to occlude high-flow, large-diameter arterial branch vessels during endovascular aortic aneurysm repair.

Endovascular stenting of an aortopulmonary fistula presenting with hemoptysis. A case report

We present a 45 year old man with massive hemoptysis due to an aortopulmonary fistula. Our patient had a history of a previous patent ductus arteriosus repair which was complicated by a previous aortopulmonary fistula. Computed tomography of the chest and aortography made the diagnosis of a recurrent aortopulmonary fistula. Because of the history of previous surgical aortic procedures, repair of the fistula was completed through a retroperitoneal aortotomy with intravascular insertion of an expandable stainless steel stent covered by a polyester graft. The patient has had no hemoptysis or computed tomographic evidence of fistula recurrence thirty eight months after the procedure.

Embolization of perigraft leaks after endovascular stent-graft treatment of aortic aneurysms

PURPOSE

Perigraft leak is one of the significant problems associated with transluminal placement of stent-grafts in the treatment of aortic aneurysms. This report describes the authors' experience with transcatheter coil embolization for the treatment of perigraft leaks.

MATERIALS AND METHODS

Ten patients who underwent transluminal placement of stent-grafts for the treatment of aortic aneurysms were treated. All patients had one or more tracts between the aortic wall and stent-graft or between two stent-grafts, resulting in residual aneurysm filling. All tracts were embolized by means of transcatheter deposition of platinum or steel coils.

RESULTS

In all patients, all tracts were embolized completely and residual aneurysm filling was eliminated. Complete thrombosis of the aneurysm was confined on follow-up spiral computed tomography in all 10 cases. Two cases required two embolization procedures to completely embolize the tracts. No recurrent leaks or aneurysm expansions were identified on follow-up studies.

CONCLUSIONS

Although long-term effectiveness remains to be proved, the initial results with transcatheter coil embolization of tracts are encouraging and suggest this technique is a safe and effective method for the management of perigraft leaks after endovascular placement of stent-grafts.

True lumen obliteration in complicated aortic dissection: endovascular treatment

PURPOSE

To evaluate endovascular treatment of ischemic complications caused by true lumen obliteration in aortic dissection.

MATERIALS AND METHODS

Endovascular techniques were used to treat true lumen obliteration in 11 patients with complicated aortic dissection. In all cases, the true lumen was compressed to a paper-thin sliver by the expanded false lumen. Two patients had Stanford type A (chronic) and nine had type B (six acute, three chronic) dissections. Obliteration of the true lumen was associated with branch vessel ischemia that included renal (n = 7), mesenteric (n = 6), and lower-extremity (n = 6) arterial compromise. Two patients were treated with aortic stents, four with balloon fenestration of the intimal flap, and three with both stent placement and fenestration. In two patients, ischemic complications caused by true lumen obliteration could not be treated with endovascular techniques.

RESULTS

Revascularization was technically successful with relief of clinical symptoms in nine patients. Revascularization was unsuccessful in one patient in whom surgical revascularization of the superior mesenteric artery was necessary and in one in whom hypertension was managed medically. One patient developed thrombosis of a renal artery in which a stent had been placed. The 30-day mortality rate was 9%, and the mean follow-up was 10.1 months (range, 2 weeks to 39 months).

CONCLUSION

True lumen obliteration can be safely and effectively treated with endovascular stent placement and balloon fenestration.

Catheter-directed thrombolysis for iliofemoral venous thrombosis

The combination of catheter-directed thrombolytic therapy and endovascular stenting is a new and promising approach for treating acute and chronic thrombotic iliofemoral venous occlusions on the basis of the authors' initial experience in a small group of patients. In acute DVT, catheter-directed techniques provide more complete lysis than systemic infusions and early, aggressive interventional therapy may spare the patient from the life-long disability associated with the postphlebitic syndrome, by preserving valve function and eliminating the venous outflow obstruction. Immediate postthrombolysis venography can evaluate the underlying vein and assess the need for adjunctive treatment with angioplasty and/or stents. Urokinase has a high degree of safety with few complications when a catheter-directed approach rather than systemic infusion is used. Even patients with chronic DVT can benefit by reducing the obstruction to venous outflow if the occlusion is limited to the iliac vein and/or the inferior vena cava. Long-term follow-up studies are necessary to evaluate patency rates of the treated veins, determine whether successfully treated limbs have a lower frequency of recurrent DVT, and ascertain the frequency of chronic venous insufficiency compared with that in patients treated with anticoagulation alone. Based on our initial experience, a National Venous Thrombosis Registry was established in October 1994. The purpose of this multidisciplinary Registry is to prospectively document the long-term results of catheter-directed thrombolytic therapy for patients with iliofemoral DVT, with data now being collected from 40 leading medical centers around the United States. We hope that endovascular techniques for iliofemoral DVT will significantly reduce the immediate and long-term complications commonly associated with this difficult and often misunderstood clinical problem.

Aortic dissection: percutaneous management of ischemic complications with endovascular stents and balloon fenestration

PURPOSE

The purpose of this study was to evaluate endovascular stenting (EVS) and balloon fenestration (BF) of intimal flaps for the management of lower extremity, renal, and visceral ischemia in acute or chronic aortic dissection.

METHODS

Twenty-two patients (16 male, 6 female) with a median age of 53 years (range 35 to 77 years) underwent percutaneous treatment for peripheral ischemic complications of 12 type A (five acute, seven chronic) and 10 type B (nine acute, one chronic) aortic dissections.

RESULTS

Ten patients had leg ischemia, 13 had renal ischemia, and 6 had visceral ischemia. Sixteen patients were treated with EVS including 11 with renal, 6 with lower extremity, 2 with superior mesenteric artery, and 2 with aortic stents. Three patients had BF of the intimal flap, and three had BF in combination with EVS. Revascularization with clinical success was achieved in all 22 patients. Two patients died 3 days and 13.4 months after the procedure was performed, respectively. Of the remaining 20 patients, 1 is lost to follow-up, and 19 have persistent relief of clinical symptoms. Mean follow-up time is 13.7 months (range 1.1 to 46.5 months). One case was complicated by guidewire-induced perinephric hematoma.

CONCLUSION

EVS and BF provide a safe and effective percutaneous method for managing peripheral ischemic complications of aortic dissection.

Hepatic laceration from wedged venography performed before transjugular intrahepatic portosystemic shunt placement

Transjugular intrahepatic portosystemic shunt (TIPS) placement is an increasingly used, nonoperative technique for treating variceal bleeding and refractory ascites secondary to portal hypertension. Since the first clinical TIPS case in 1989, the procedure has undergone significant technical refinement to improve the safety and efficacy of shunt placement. A major technical challenge of TIPS creation is passage of the transjugular needle from the hepatic vein into the portal vein. Perforation of the liver capsule from an errant needle pass can lead to massive intraperitoneal bleeding. To minimize the number of needle passes required to enter the portal vein, investigators have devised a variety of techniques to visualize the portal vein anatomy including direct transhepatic catheterization of the portal vein, superior mesenteric artery (SMA) angiography, real-time ultrasound (US) guidance and refluxing contrast medium into the portal vein with wedged hepatic venography. While these technical improvements have made TIPS a safe and attractive alternative to conventional surgical shunts, the procedure remains technically challenging and lethal hemorrhagic complications can occur when the liver capsule is perforated during the course of the procedure. To our knowledge, there are no reported major complications directly related to the wedged hepatic venogram prior to TIPS. We describe an unusual series of severe liver injuries from wedged hepatic venography during attempts to localize the portal vein.

Percutaneous endoluminal placement of stent-grafts for the treatment of isolated iliac artery aneurysms

PURPOSE

To evaluate the feasibility of stent-grafts for treatment of isolated iliac artery aneurysms (IAAs).

MATERIALS AND METHODS

Nine IAAs in eight patients were treated with transluminally placed endovascular stent-grafts. All patients were men (median age, 72 years). In three, the aneurysm involved both the common and internal iliac arteries. In one, common and external iliac arteries were involved. The other aneurysms involved only the common iliac artery. Two aneurysms were treated with balloon-expandable stents covered with polytetrafluoroethylene (PTFE) graft material, three were treated with self-expanding Z-stents covered with a woven polyester graft, and four were treated with self-expanding Z-stents covered with PTFE.

RESULTS

Transluminal placement of the stents was successful in all patients with thrombosis of the aneurysms. There were no distal thromboembolic events, deaths, or infections. The median follow-up period was 8.5 months.

CONCLUSION

Initial results suggest that transluminal stent-graft placement for treating isolated IAAs is a safe and effective alternative to surgery in selected patients. Long-term follow-up data are needed before this approach can be recommended for the primary treatment of IAAs.

Endovascular stent-grafting after arch aneurysm repair using the "elephant trunk"

A 68-year-old woman with severe chronic obstructive pulmonary disease, aortic valvular insufficiency, and diffuse thoracic aortic aneurysm underwent aortic valve replacement and separate Dacron graft replacement of the ascending aortic and arch aneurysms using the elephant trunk technique. She was discharged on the tenth postoperative day. Five months later, she underwent endovascular stent-graft repair of the descending thoracic aortic aneurysm. She recovered uneventfully, and was discharged on the third postoperative day. Follow-up computed tomography at 6 months demonstrated exclusion of all flow into the descending thoracic aortic aneurysm. The elephant trunk technique followed by endovascular stent-grafting of the descending thoracic component is a potential therapeutic option in selected high-risk patients with diffuse aortic aneurysmal disease.