Endovascular abdominal aortic aneurysm repair in 144 patients: correlation of aneurysm size, proximal aortic neck length, and procedure-related complications.

PURPOSE: During endovascular abdominal aortic aneurysm (AAA) repair, larger aneurysms often present formidable anatomic challenges to the insertion of the delivery catheter and graft deployment. The authors sought to evaluate whether large-diameter aneurysms and those with short proximal aortic necks might be associated with a higher frequency of insertion-related and short-term complications. MATERIALS AND METHODS: From October 1999 to August 2000, 144 patients underwent elective endovascular graft placement for infrarenal AAA disease at the authors' institution. These patients were treated with use of the AneuRx bifurcated endoprosthesis. AAA size (maximum aneurysm diameter) and proximal aortic neck length were compared to estimated blood loss, operative time, accuracy of graft placement, presence of endoleak, intraoperative and postoperative complications (such as limb occlusion or vascular injury), length of hospital stay, and mortality. Statistical methods included correlation analysis and logistic regression. RESULTS: There were 121 men and 23 women whose aneurysms ranged in size from 3 cm to 9.8 cm (mean, 5.6 cm; 95% CI, 5.4-5.8 cm). Endograft insertion was successful in all cases. There were three deaths within 30 days (2.1%) and seven deaths overall (4.9%). There were 43 intraoperative complications (29.9%) in 31 patients (21.5%), most of them minor. Patients with major intraoperative complications had significantly longer procedure times than those without complications (337 vs. 149 min; P <.0001). In the postoperative period (within 30 days), 31 complications (21.5%) occurred in 28 patients (19.4%), again most of them minor. AAA size was unrelated in any way to the rate of complications, but short proximal aortic neck length was associated with more serious intraoperative and postoperative complications (P =.0404 and P =.0230, respectively), and decreased 30-day and overall survival (P =.0240 and P =.0152, respectively). CONCLUSIONS: Endovascular repair of large AAAs can be challenging; however, the size of the AAA does not influence the rate of complications. A short proximal aortic neck is the only significant risk factor for more serious complications.

Use of aortic cuffs to exclude iliac artery aneurysms during AneuRx stent-graft placement: initial experience.

PURPOSE: As many as 39% of patients who undergo aortic endografting for abdominal aortic aneurysm disease will have ectasia of the iliac arteries that will require intervention. Coil embolization of the internal iliac artery and extension of the graft to the external iliac artery is one solution to this problem. However, 19%-41% of these patients experience buttock claudication, which may be permanent, after unilateral embolization. The authors examined an alternative: the use of larger-sized aortic cuffs to seal the iliac limb. Outcomes and short-term results are presented in this article. MATERIALS AND METHODS: From October 1999 to August 2000, 144 AneuRx stent-grafts were placed at the authors' institution. Among the population receiving stent-grafts, 14 patients had 15 aortic cuffs placed across the distal iliac graft limbs to seal them and preserve flow to the internal iliac artery. One patient had bilateral cuffs placed. Five patients had embolization of the contralateral internal iliac artery because of bilateral disease. Patients were followed with computed tomography (CT) at 1, 6, and 12 months to evaluate for endoleaks. RESULTS: One- and 6-month endoleak rates, determined from only those patients with follow-up CT, were 0% and 10%, respectively. One type II endoleak was first discovered 9 months after graft placement. It sealed spontaneously at 15-month follow-up. One patient among the five who had internal iliac artery embolization had claudication. Mean CT follow-up was 7.8 months (range, 1-15). One patient declined CT but was alive and well 11 months after endografting. One patient moved across the country and declined follow-up. CONCLUSION: Placement of aortic cuffs in dilated iliac arteries can preserve flow to the ipsilateral internal iliac artery and provide an adequate seal. Additionally, the option of later treatment is maintained. Patients with bilateral iliac ectasia can undergo stent-graft placement without bilateral internal iliac artery embolization. Longer-term follow-up in larger numbers of patients will be important to determine the ultimate durability of this technique.

Endoluminal graft repair for abdominal aortic aneurysms in high-risk patients and octogenarians: is it better than open repair?

OBJECTIVE: To analyze the short-term and midterm results of open and endoluminal repair of abdominal aortic aneurysms (AAA) in a large single-center series and specifically in octogenarians. METHODS: Between January 1997 and October 2000, 470 consecutive patients underwent elective repair of AAA. Conventional open repair (COR) was performed in 210 patients and endoluminal graft (ELG) repair in 260 patients. Ninety of the patients were 80 years of age or older; of these, 38 underwent COR and 52 ELG repair. RESULTS: Patient characteristics and risk factors were similar for both the entire series and the subgroup of patients 80 years or older. The overall complication rate was reduced by 70% or more in the ELG versus the COR groups. The postoperative death rate was similar for the COR and ELG groups in the entire series and lower (but not significantly) in the ELG 80 years or older subgroup versus the COR group. The 36-month rates of freedom from endoleaks, surgical conversion, and secondary intervention were 81%, 98.2%, and 88%, respectively. CONCLUSION: The short-term and midterm results of AAA repair by COR or ELG are similar. The death rate associated with this new technique is low and comparable, whereas the complication rate associated with COR in all patients and those 80 years or older in particular is greater and more serious than ELG repair. Long-term results will establish the role of ELG repair of AAA, especially in elderly and high-risk patients.

Evolution of vascular fellowship training in the new era of endovascular techniques.

PURPOSE: The endovascular technique has revolutionized the treatment of infrarenal abdominal aortic aneurysm (AAA). At our institution, we examined the impact of an endovascular program on the traditional operative training of the vascular fellows in the treatment of infrarenal AAA. METHODS: We examined the records of our vascular fellows' experience from July 1995 to May 2000. We introduced the endovascular treatment for infrarenal AAA in 1995. RESULTS: The fellows have performed increasing numbers of endovascular cases each year, with a predicted number of 124 cases for 1999-2000. However, despite an increase in the overall volume of patients with infrarenal AAA (102 cases in 1998-1999 and a predicted 160 cases in 1999-2000), the trainees will experience a reduction in the number of open AAAs from 61 cases in 1998-1999 to a predicted 36 cases in 1999-2000. However, the volume of open suprarenal AAA has also increased from eight cases in 1998 to 1999 to a predicted 24 cases in 1999-2000. With no significant change in the open aortoiliac occlusive cases from previous years, the current fellows will graduate with a similar volume of open aortic procedures as their predecessors. CONCLUSION: With the recent advances in endovascular technology, our traditional operative approach to the treatment of AAA disease may be lacking in the training of future vascular surgeons. At our institution, although fewer open infrarenal AAA cases were performed, the trainees have maintained the open aortic experience by performing an increased volume of suprarenal AAAs. We have to critically reevaluate and redefine what constitutes adequate vascular fellow experience in the surgical treatment of abdominal aortic aneurysms.

The Hemobahn endoprosthesis: a self-expanding polytetrafluoroethylene-covered endoprosthesis for the treatment of peripheral arterial occlusive disease after balloon angioplasty.

Endoluminal management of occlusive arterial disease has previously been limited to balloon angioplasty, either alone or with stent placement. This article discusses the Hemobahn endoprosthesis, a polytetraflouroethylene-covered nitinol stent graft. The Hemobahn device design characteristics, Food and Drug Administration phase I feasibility trial design and results, phase II pivotal trial design, and single-site phase II trial results are reviewed. The long-term outcomes of patients treated with angioplasty and Hemobahn stent grafting will determine the role of stent grafting in the management of occlusive arterial lesions below the aortic bifurcation.

Preoperative treatment with doxycycline reduces aortic wall expression and activation of matrix metalloproteinases in patients with abdominal aortic aneurysms.

PURPOSE: Matrix metalloproteinases (MMPs) are considered to play a central role in the pathogenesis of abdominal aortic aneurysms (AAAs). Doxycycline (Dox) has direct MMP-inhibiting properties in vitro, and it effectively suppresses the development of elastase-induced AAAs in rodents. The purpose of this study was to determine if treatment with Dox suppresses MMPs within human aneurysm tissue and to elucidate the molecular mechanisms underlying this effect. METHODS: Aneurysm tissues were obtained from 15 patients with an AAA, eight of whom had been treated with Dox before surgery (100 mg orally twice a day for 7 days). Protein extracts were examined by means of gelatin zymography and immunoblot analysis, and RNA was examined by means of reverse transcription-polymerase chain reaction (RT-PCR). The effects of Dox on MMP production were further examined in human THP-1 mononuclear phagocytes in vitro. RESULTS: No detectable difference was found between groups by using substrate zymography as a means of assessing total MMP activity, but Dox treatment was associated with a slight (24.4%) reduction in the activated fraction of 72-kDa gelatinase (MMP-2; P <.05). In contrast, a 2.5-fold reduction in the amount of extractable 92-kDa gelatinase (MMP-9) protein in Dox-treated patients was revealed by means of immunoblot analysis (P <.05). Also, a 5.5-fold (81.9%) reduction in MMP-9 messenger RNA (mRNA) in Dox-treated patients was demonstrated by means of quantitative competitive RT-PCR (mean +/- SE, mol MMP-9/mol beta-actin: 1.3 +/- 0.5 vs 7.2 +/- 3.1; P <.04). There was no significant difference between groups in the relative expression of MMP-2 protein or mRNA. In cultured THP-1 monocytes stimulated with phorbol ester, the expression of MMP-9 protein and mRNA were both decreased after exposure to relevant concentrations of Dox in vitro. CONCLUSION: In addition to its recognized effects as a direct MMP antagonist, Dox may influence connective tissue degradation within human aneurysm tissue by reducing monocyte/macrophage expression of MMP-9 mRNA and by suppressing the post-translational processing (activation) of proMMP-2. Through this complementary combination of mechanisms, treatment with Dox may be a particularly effective strategy for achieving MMP inhibition in patients with an AAA.

Criteria for outpatient management of proximal lower extremity deep venous thrombosis.

STUDY OBJECTIVES: To develop and to evaluate selection criteria for outpatient management of deep venous thrombosis (DVT). DESIGN: We developed outpatient treatment eligibility criteria that incorporated demographic and clinical data. We aimed to exclude patients at high risk for bleeding or recurrent clotting, as well as those with pulmonary embolism, limited cardiopulmonary reserve, or need for hospitalization due to another illness. Then, we retrospectively applied the criteria to hospitalized patients with newly diagnosed proximal lower extremity DVT to determine the fraction of patients eligible for outpatient therapy; patients were classified as eligible, possibly eligible, or ineligible for home treatment based on the selection criteria. SETTING: University hospital. PATIENTS: One hundred ninety-five hospitalized patients diagnosed as having proximal lower extremity DVT by duplex ultrasound over a 1-year period. MEASUREMENTS: Frequency of complications during initial DVT therapy, including major bleeding, symptomatic thromboembolism, and death. RESULTS: Eighteen (9%) patients were classified as eligible, and 18 (9%) were classified as possibly eligible for outpatient therapy. None of these patients developed complications. Of the 159 (82%) patients classified as ineligible, 13 (8%; 95% confidence interval [CI], 4 to 12%) died or developed serious complications. Therefore, the eligibility criteria had a sensitivity of 100% (95% CI, 92 to 100%) and a negative predictive value of 100% (95% CI, 92 to 100%) for predicting serious complications. CONCLUSIONS: Specific eligibility criteria may identify a subset of patients with acute DVT who can be treated safely at home.

Intraabdominal hemorrhage during combined coronary artery bypass and carotid endarterectomy.

Intraabdominal complications during cardiopulmonary bypass are extremely rare, with an incidence of less than 1% in multiple retrospective studies. These complications are associated with a high mortality, and their rapid diagnosis is critical to the outcome of the patient. We present a case of spontaneous intraabdominal hemorrhage after combined carotid endarterectomy and four-vessel coronary artery bypass grafting, which was diagnosed through a diaphragmatic window.

Surgical treatment of patients with symptomatic vertebrobasilar insufficiency.

We report our experience with surgical management of symptomatic vertebrobasilar insufficiency (VBI). Forty revascularizations were carried out in 39 patients over 90 months. Dizziness (52%) and syncope/presyncope (32%) were the most common symptoms. Arteriography was performed in all patients, with subclavian steal seen in 55% of patients. Procedures performed included 22 cases of carotid-subclavian bypass or transposition (55%), seven direct vertebral reconstructions (17.5%), four great vessel reconstructions (10%), four isolated carotid endarterectomies (10%), and three axilloaxillary bypasses (7.5%). One patient died, and the combined morbidity and mortality rate was 15%. Outpatient follow-up was available on 37 of the 38 patients discharged alive. At a mean follow-up of 16.4 months, 34 patients had no VBI complaints. Three of four patients treated with CEA alone had persistent VBI complaints. We conclude that a variety of anatomic lesions can result in VBI symptoms, with subclavian steal being the most common. Procedures which directly correct the anatomic abnormality result in sustained symptom resolution with acceptable complication rates.

Endovascular stent grafts for aneurysmal and occlusive vascular disease.

BACKGROUND: This report details our initial experience with two types of endovascular grafts- one for the treatment of infrarenal abdominal aortic aneurysms and the other for the treatment of iliac artery occlusive disease. METHODS: An abdominal aortic aneurysm was repaired in 34 patients using 3 different types of Ancure endografts (Menlo Park, California). Control patients (n = 9) had a standard aneurysm repair. Patients with chronic lower extremity ischemia (n = 7) secondary to iliac artery occlusive disease were treated with a Hemobahn endograft (W. L. Gore & Associates, Flagstaff, Arizona). RESULTS: Ancure graft deployment was achieved in 33 of 34 (97.1%) patients. Perioperative mortality for the Ancure and control group patients was 2.9% and 0%, respectively. Periprosthetic leaks were identified within 48 hours of deployment in 6 (18.2%) Ancure graft patients. All but 2 of the leaks resolved on serial follow-up. Additional endovascular procedures were required in 11 (32.4%) Ancure graft patients at the initial procedure or during follow-up to correct graft or arterial stenoses. Patients treated with an endovascular graft had significantly less blood loss and shorter hospital stays than control group patients. For Hemobahn patients, the technical success for graft deployment was 100%. There were no perioperative deaths. The ankle/brachial index increased from a mean of 0.52 preoperatively to 0.86 postoperatively (P = 0.004). One patient required a Wallstent in follow-up to correct a graft wrinkle. Angiography at 6 months demonstrated mild intimal hyperplasia in the stent graft in 5 of 6 patients. CONCLUSIONS: These early results support the potential for endovascular grafts in the treatment of aneurysmal and occlusive vascular disease. Further modifications in the devices and deployment techniques are necessary to reduce the incidence of periprosthetic leaks, graft limb stenoses, and intimal hyperplasia.

Arterial thrombosis induces early upregulation of intercellular adhesion molecule in the media.

PURPOSE: Thrombosed peripheral vessels that are pharmacologically or mechanically recanalized have diminished long-term patency rates compared with vessels that are repaired before occlusion. We hypothesized that thrombosis induces proinflammatory changes in the arterial media that may contribute to postthrombotic vascular remodeling. METHODS: We studied expression of intercellular adhesion molecule (ICAM), a mediator of leukocyte recruitment, in the arterial wall after thrombosis. Thrombosis was induced in rabbit superficial femoral arteries by embolizing polystyrene beads (Thr-emb) or by ligation (Thr-lig). Control vessels were dissected but not ligated (C-dis) or were subjected to bead embolization and immediate removal (C-emb). Arterial wall ICAM expression was measured by indirect immunohistochemical analysis at 6 hours, 24 hours, and 1 week. Staining intensity was graded from 0 (none) to 4 (intense) by observers who were blinded to the experimental conditions. RESULTS: No increase in ICAM expression by thrombosed vessels was present at 6 hours. After 24 hours, ICAM expression in the media of thrombosed vessels was increased (Thr-emb, 2.3 +/- 0.5; Thr-lig, 2.0 +/- 0) compared with control vessels (C-dis, 0 +/- 0; C-emb, 0.8 +/- 0.5; p < 0.004). This difference became more marked at 1 week. ICAM staining localized to actin-staining regions of the media. CONCLUSIONS: Arterial thrombosis, but not surgical injury, induces pronounced early and sustained upregulation of ICAM expression in smooth muscle-containing regions of the arterial media. Upregulation of ICAM is likely to promote recruitment of inflammatory cells or mediate vascular remodeling after luminal thrombosis.

Spontaneous closure of selected iatrogenic pseudoaneurysms and arteriovenous fistulae.

PURPOSE: We report our approach to the management of postcatheterization femoral artery pseudoaneurysms and arteriovenous fistulae in an attempt to determine the frequency of spontaneous resolution of selected lesions. METHODS: We studied 196 pseudoaneurysms, 81 arteriovenous fistulae, and 9 combined lesions that were identified by duplex scan. Indications for immediate surgical repair included pseudoaneurysm greater than 3 cm, enlarging hematoma, pain, groin infection, nerve compression, limb ischemia, concomitant surgical procedure, and patient refusal or inability to comply with follow-up. All other lesions were observed. RESULTS: One hundred thirty-nine patients underwent prompt surgical repair, and 147 patients were initially managed without operation. There were no limb-threatening complications associated with nonoperative management in this subset of patients. Eighty-six percent of the lesions being observed resolved spontaneously within a mean of 23 days, whereas 14% required surgical closure for a variety of reasons (at a mean of 111 days after the initial diagnosis). There was no statistically significant difference in the rate of spontaneous pseudoaneurysm closure (89%) as opposed to fistulae (81%) (p < 0.17). By life-table analysis, 90% of selected pseudoaneurysms had resolved by 2 months. Patients selected for observation underwent an average of 2.6 duplex scans per patient versus 1.4 scans per patient for those treated with immediate surgery (p < 0.01). CONCLUSION: The natural history of stable pseudoaneurysms and arteriovenous fistulae is benign and frequently results in spontaneous resolution, which allows properly selected patients to be managed without operation.

Thrombogenicity of small-diameter prosthetic grafts: relative contributions of graft-associated thrombin and factor Xa.

PURPOSE: We evaluated the contributions of coagulation factors IIa (thrombin) and Xa to small-diameter prosthetic graft thrombogenicity in vivo. METHODS: Preclotted and nonpreclotted (collagen-coated) polyester grafts were studied before and 24 hours after implantation into pig femoral arteries. After incubation of explanted grafts was performed with plasma depleted of vitamin K-dependent coagulation factors by barium chloride adsorption (Ba-plasma), graft-associated thrombin activity was determined by radioimmunoassay for fibrinopeptide A. Fibrinopeptide A levels reflect thrombin-mediated fibrin formation. Factor Xa activity was characterized by measuring activation of prothrombin added to Ba-plasma. RESULTS: Thrombin and factor Xa were associated with the luminal surfaces of preclotted grafts before and 24 hours after implantation. Nonpreclotted grafts had negligible procoagulant activity before implantation. After 24 hours in vivo graft-associated factor Xa activity was similar in both nonpreclotted and preclotted grafts; however, more thrombin was bound to nonpreclotted coated grafts (p < 0.01). CONCLUSIONS: The procoagulant activity of small-diameter prosthetic grafts persists for 24 hours after implantation and is attributable not only to graft-associated thrombin but also to de novo thrombin elaboration induced by factor Xa. Moreover, graft-associated procoagulant activity is not dependent on preclotting because it develops on nonpreclotted, collagen-coated grafts as well. Treatment strategies to attenuate graft thrombosis may require the inhibition of both thrombin and factor Xa.

Safety, feasibility, and early efficacy of subfascial endoscopic perforator surgery: a preliminary report from the North American registry.

PURPOSE: The North American Subfascial Endoscopic Perforator Surgery (NASEPS) Registry was established to evaluate the safety, feasibility, and efficacy of minimally invasive endoscopic Linton operations for treatment of chronic venous insufficiency. METHODS: Retrospective analysis was performed on the clinical data of 151 patients who underwent attempt at 158 SEPS in 17 medical centers in the United States and Canada between June 1993 and February 1996. RESULTS: SEPS was completed on 155 limbs of 148 patients, 81 male and 67 female (mean age, 56 years; range, 27 to 87 years). Three procedures were aborted. Seven patients had bilateral procedures (data from one limb were analyzed). One hundred four limbs (70%) had active ulcers, and 22 (15%) had healed ulcers. A single endoscopic port without insufflation was used in 66 procedures (45%) and laparoscopic instrumentation, with two or three ports, in 82 (55%), with CO2 insufflation in 78 (53%). A tourniquet was used on 112 patients (76%). Concomitant venous procedures were performed in 106 patients (72%; saphenous stripping in 71, high ligation in 17, varicosity avulsion in 85). No early deaths or thromboembolism occurred. Complications included wound infections (9), superficial thrombophlebitis (5), cellulitis (4), and saphenous neuralgia (10). Seven patients with wound infection had open ulcers; nine of 10 with neuralgia had concomitant procedures. A roll-on tourniquet caused skin necrosis in one patient. The clinical score improved from 9.4 to 2.9 after surgery (p < 0.0001). Mean follow-up was 5.4 months; 31 patients had > or = 6 months follow-up. Ulcers healed in 88% (75 of 85); recurrence or new ulcer was reported in 3% (4 of 120). CONCLUSIONS: The SEPS modified Linton operation appears safe, with no postoperative deaths or early thromboembolism. Wound infection after SEPS remains important. Early results indicate rapid ulcer healing. Prospective evaluation of long-term results is warranted.

Preincubation of Dacron grafts with recombinant tissue factor pathway inhibitor decreases their thrombogenicity in vivo.

BACKGROUND: We have previously shown that preincubation of whole blood clots with recombinants tissue factor pathway inhibitor (rTFPI) attenuates clot-associated procoagulant activity assessed ex vivo. This study was undertaken to determine whether a single local application of rTFPI induces similar attenuation of the procoagulant activity on preclotted Dacron grafts implanted in an artery in vivo. METHODS: Dacron grafts (4 mm x 4 cm long) were preclotted in porcine blood and incubated with either rTFPI (5 mg/ml) or arginine-phosphate buffer for 15 minutes. Grafts were implanted end-to-end in the femoral arteries of 10 pigs, with one rTFPI-treated and one buffer-treated graft implanted in each animal. Animals did not undergo anticoagulation either before or after graft implantation. Radiolabeled porcine fibrinogen was injected intravenously, and the grafts underwent perfusion for 1 hour. A subgroup of animals (n = 7) also had infusion of radiolabeled autologous platelets at the time of administration of radiolabeled fibrinogen. RESULTS: Fibrin(ogen) deposition was decreased in rTFPI-treated grafts by 36% +/- 7% (mean +/- SEM) compared with buffer-treated grafts (p = 0.001). Platelet deposition was also reduced in the rTFPI-treated grafts by 31% +/- 15%, although the reduction did not reach statistical significance (p = 0.10). The extent of rTFPI-mediated attenuation of fibrin(ogen) versus platelet deposition varied independently among animals. CONCLUSIONS: Clot-directed anticoagulant effects of rTFPI appear to be useful for substantially decreasing the thrombogenicity of Dacron grafts immediately after their implantation. Chronic studies to determine whether the decreases in thrombogenicity result in improved long-term graft patency appear warranted.