Late Graft Occlusion Research Articles

Vein Graft Harvesting Induces Inflammation and Impairs Vessel Reactivity

Saphenous veins are often used for coronary artery bypass grafting (CABG), but loss of patency is a problem. The surgical procedure may contribute to graft injury. Our aim was to study the impact of surgical handling of saphenous veins on graft inflammation and vascular function. Biopsy samples of saphenous veins were taken from 9 patients undergoing elective CABG at the start of vein harvesting (open technique) and after the last proximal anastomosis was sutured. Messenger RNA was extracted and amplified with semiquantitative reverse transcription polymerase chain reaction. Gene expression of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta), leukocyte adhesion molecules (E-selectin, intercellular adhesion molecule-1), and vasoactive substances (endothelin-1, inducible and endothelial nitric oxide synthase) was investigated. Translocation of nuclear factor-kappaB (NFkappaB) was evaluated with electrophoretic mobility shift assay. Immunostaining for von Willebrand factor was performed to evaluate loss of endothelium, and in vitro vein reactivity to phenylephrine and endothelin-1 was studied. Gene expression of cytokines and leukocyte adhesion molecules increased after graft harvesting and storage, whereas vasoactive substances did not change. Nuclear translocation of NFkappaB occurred after surgical handling, concurrent with partial loss of endothelium and impaired contractile function. Standard surgical handling of vein grafts induces NFkappaB-driven inflammation in the vessel wall and impairs vascular function. This may potentially contribute to both early and late graft occlusion.

Vascular-wall remodeling of 3 human bypass vessels: Organ culture and smooth muscle cell properties

Late graft occlusions after coronary artery bypass grafting have been ascribed to neointimal hyperplasia. Given the pivotal role of smooth muscle cells in the pathogenesis of neointimal hyperplasia and the phenotypic heterogeneity of smooth muscle cells across vessels, we hypothesized that differences in long-term graft patency are at least partly related to differences in smooth muscle cell properties. The aim of the present study was to compare the vascular-wall remodeling of human internal thoracic artery, radial artery, and saphenous vein bypass conduits. We evaluated the intimal thickening of the human graft segments in organ cultures (histopathology, morphometric, and immunofluorescence analyses) and assessed the properties of cultured smooth muscle cells isolated from these vessels in terms of cell proliferation (tritiated thymidine incorporation), migration (modified Boyden chamber), and collagen synthesis (tritiated proline incorporation). The total vessel-wall growth index and the intimal growth index were significantly higher for saphenous vein rings than for radial artery and internal thoracic artery rings. Immunofluorescence analyses showed predominant involvement of smooth muscle cells in neointimal growth induced by organ culture of saphenous vein rings. Cell proliferation was significantly higher in saphenous vein smooth muscle cells than in radial artery smooth muscle cells and significantly higher in radial artery smooth muscle cells than in internal thoracic artery smooth muscle cells. Migration of smooth muscle cells from saphenous vein grafts was significantly greater than from internal thoracic artery or radial artery grafts. Collagen synthesis was similar in smooth muscle cells from internal thoracic artery, radial artery, and saphenous vein grafts. Ex vivo vascular-wall remodeling and smooth muscle cell intrinsic growth and migratory properties are dissimilar between arterial and venous grafts and might shed light on reported angiographic patency rates of these grafts.

Late Graft Occlusion of Axillofemoral Bypass after the Repair of an Infected Aortic Aneurysm: Revascularization Using the Descending Aorta As an Inflow Source

Late Graft Occlusion of Axillofemoral Bypass after the Repair of an Infected Aortic Aneurysm: Revascularization Using the Descending Aorta As an Inflow Source

Survey of the use of thrombolysis for acute limb ischaemia in the UK and Ireland

A total of 156 vascular surgeons from the UK and Ireland responded to a postal questionnaire on the use of thrombolysis in acute limb ischaemia. Almost half had used thrombolysis in the previous 12 months. Low dose intra-arterial streptokinase (89 per cent) was the regimen most frequently used, but 33 per cent had used intravenous streptokinase. Detailed results for 103 patients (limb salvage rate 60 per cent, amputation rate 35 per cent, mortality rate 5 per cent) were similar to those of previously published reports. Complications in most series were infrequent, but in the entire survey there were six bleeding-related deaths and one death from anaphylaxis. A total of 67 per cent of surgeons with working experience indicated that selected patients with acute arterial thromboses were most suitable for thrombolysis, particularly if there was no neurological deficit and no run-off for surgical bypass. Distal or late emboli and graft occlusions were regarded as appropriate by some surgeons. This study demonstrated that many vascular surgeons currently use thrombolysis, although sparingly and in selected cases. Patients with acute limb ischaemia should be managed by experienced vascular surgeons who are aware of the new therapeutic alternatives, an ideal supported by almost three-quarters of respondents to this survey.

Graft occlusion following aortofemoral bypass for peripheral ischaemia.

Over a 10-year period, 241 patients with non-aneurysmal aortoiliac disease underwent aortofemoral bypass to 476 limbs. Four patients (1.7 per cent) occluded their grafts within 30 days of surgery, while 25 (10.4 per cent) suffered late graft occlusion. Postoperative occlusions were associated with significant morbidity and only one patient avoided major limb amputation or death. Overall, 46 episodes of graft thrombosis involving 51 graft limbs were encountered, the most common underlying cause being pre-existing or progressive multilevel distal occlusive disease. The overall cumulative graft patency rates were 95 and 87 per cent at 1 and 5 years respectively. Cumulative 5-year patency was significantly higher in patients presenting with claudication (91 per cent) than in patients presenting with rest pain (77 per cent) or ulceration and/or gangrene (71 per cent). Patients with evidence of multilevel distal occlusive disease at the time of aortic surgery had a significantly higher incidence of occlusion compared with those in whom there was no significant distal disease. In 35 episodes of occlusion (76 per cent), surgery was undertaken to restore limb blood flow, being successful in all but one case, with the most commonly performed procedure being graft limb thrombectomy. Seven of 28 patients (25 per cent) ultimately required major limb amputation and three patients died as a direct consequence of graft thrombosis.

Coronary Artery Surgery

Coronary Artery Surgery

Total arterial off-pump coronary revascularization with only internal thoracic artery and composite radial artery grafts.

Total arterial off-pump coronary artery bypass (OPCAB) grafting with only internal thoracic artery (ITA) and composite radial artery (RA) grafts has been applied extensively to avoid cerebral complications and late vein graft failure. We evaluated the initial experience with this method by clinical and angiographic study. Between April 2000 and May 2002, 257 patients underwent OPCAB grafting with this technique. The range of ages at operation was 42 to 86 years (mean, 66.1 +/- 8.6 years). On average, 3.28 +/- 0.86 grafts per patient were completed. More than 4 distal anastomoses were performed in 88 patients (34%). For coronary revascularization, 289 ITA and 555 RA grafts were used. The RA was used as a Y graft in 211 patients, as an I graft (for ITA extension) in 52 patients, and as a K graft (the side of the RA attached to the side of the left ITA) in 28 patients. Sequential bypass grafting was performed with 190 RA and 7 ITA grafts. The sites of distal anastomoses were 256 left anterior descending arteries (30%), 236 posterolateral branches (28%), 144 posterior descending arteries (17%), 106 diagonal branches (13%), 82 obtuse marginal branches (10%), and 19 right coronary arteries (2%). There were 1 operative death (0.4%) due to cerebral hemorrhage and 2 episodes of stroke (0.8%) during postoperative angiography. There were no clinical underperfusion syndromes or new intra-aortic balloon pump insertions. Perioperative myocardial infarction occurred in 12 patients (4.7%), sternal dehiscence in 5 (1.9%), and early coronary intervention in 4 (1.6%). There was no deep wound infection, reexploration for bleeding, or hand ischemia. The actuarial survival rate and the cardiac event-free rate at 2 years were 98.6% +/- 2.4% and 94.2% +/- 0.8%, respectively. Early postoperative angiography revealed a 97.8% (264/270) graft patency of ITAs and 97.9% (512/523) graft patency of RAs in 238 patients. Flow competition of the RA graft was recognized in 22 patients and, as indicated by follow-up angiographic study, did not cause late graft occlusion. OPCAB grafting with ITAs and composite RAs provides excellent early and intermediate clinical results and graft patency.

Total arterial myocardial revascularization: analysis of initial experience

BACKGROUNDTotal arterial myocardial revascularization is an attempt to overcome the problems of late vein graft atherosclerosis, occlusion and need for coronary re-operations. Despite increasing evidence of efficacy, the use of arterial conduits has not been accepted as a primary practice in most of the centers in Pakistan for various reasons. We analyze our initial experience to assess the feasibility of total arterial revascularization as a primary strategy in patients requiring first time coronary artery bypass grafting.METHODSTwo hundred patients undergoing first time CABG at our institution, from January 2000 to April 2001, were studied. Group 1 consisted of 100 patients undergoing total arterial revascularization (using bilateral internal thoracic and radial arteries) and Group 2 consisted of 100 patients undergoing conventional CABG (using one internal thoracic artery and supplemental veins). Thirty-day mortality and early morbidity with particular reference to resternotomy for bleeding, cerebrovascular accidents, renal failure, and sternal dehiscence were the main outcome measures.RESULTSPatients in Group 1 were younger (56.2±10.4 vs. 60.3±9.8 years; P<0.001), had lower Parsonnet scores (4.8±0.4 vs. 9.6±1.8; P<0.001), and had better left ventricular function. Both groups received a similar number of grafts. The percentage of patients undergoing total arterial revascularization rose from 20% in the first three months to over 65% in the three later three-month periods. Overall 30-day mortality was 1.5%, one patient (1%) in Group 1 and two patients (2%) in Group 2. There was a similar incidence of postoperative complications and length of median postoperative stay in both groups.CONCLUSIONTotal arterial revascularization can be adopted as a primary strategy in most patients undergoing CABG with no increase in mortality or morbidity.

Late saphenous vein graft occlusion in patients with coronary bypass: possible role of aspirin resistance

Background: Late venous graft thrombosis, leading to recurrent ischemia, is frequently encountered in old, degenerated vein grafts with advanced atherosclerotic plaque formation. Aspirin has been indicated to maintain venous graft patency in the post-operative period. However, there is considerable evidence that aspirin resistance is of concern in patients with venous grafts. Material and Method:Prospectively enrolled 14 patients (11 male, 3 female, Group 1), who were shown to have at least one occluded saphenous vein graft on their late control coronary angiogram after bypass operation, were compared for the presence of aspirin resistance by PFA-100 with age- and sex-matched 14 patients (10 male, 4 female, Group 2), who were found patent and well-functioning vein grafts without wall irregularities on late post-operative coronary angiograms (mean 6.5±2.5 years), enrolled as a control group. Results: Mean CT of collagen/epinephrine cartridge in Group 1 was 197±85 s and significantly less than in Group 2 (279±44 s; p=0.011). It was found that 50% of patients in Group 1 were so-called aspirin resistant, whereas in Group 2, this ratio was 7.1% ( p=0.033). BMI ( p=0.038, Beta=−0.322), uric acid level ( p=0.023, Beta=−0.355), and CT by collagen/epinephrine cartridge ( p=0.008, Beta=0.431) were independently predicting late occlusion of saphenous vein graft. Conclusion: Aspirin resistance is highly prevalent in patients with occluded venous grafts at a relatively late period.

Laparoscopy-assisted reconstruction to treat severe aortoiliac occlusive disease: early and midterm results

Objectives The purpose of this study was to evaluate the consequences on patient selection and on early and midterm results of the learning curve of a surgical team performing laparoscopy-assisted surgery in the treatment of severe aortoiliac occlusive disease (AIOD). Patients and method Between January 1998 and June 2003, 58 patients (53 men, 5 women; mean age, 59.5 years [range, 37-76 years]) were included in a prospective study and underwent a laparoscopy-assisted aortofemoral reconstruction with graft implantation through a 5-cm to 8-cm minilaparotomy. Fifty-one patients (88%) had claudication (category 2 or 3, Rutherford classification), and seven patients (12%) had tissue loss; at presentation they had TransAtlantic Inter-Society Consensus C (n = 24, 41.4 %) or D (n = 32, 55.2%) iliac lesions, and the last 2 patients (3.4%) had severe aortic lesions. Perioperative data for the first 29 patients, obtained during the first 34 months of the study (group 1), were compared with data for the last 29 patients, obtained during the last 32 months of the study (group 2). Follow-up consisted of clinical examination or duplex scanning, or both, at 1, 3, 6, and 12 months and yearly thereafter, and computed tomography before discharge and then every 2 years. Results One intraoperative surgical conversion (1.7%) was necessary, and two other patients (3.4%) died in the immediate postoperative period. With experience, initial contraindications such as obesity or suprarenal artery aortic clamping were eliminated, making it possible to increase the percentage of patients included, from 53.7% during the first 34 months to 90.6% during the last 32 months ( P = .003). The mean duration of the operative procedure decreased from 285 minutes in group 1 to 192 minutes in group 2 ( P < .001), and the mean duration of aortic clamping decreased from 76.4 minutes in group 1 to 31.8 minutes in group 2 ( P < .001). The number of early repeat interventions was reduced from three (10.3%) in group 1 to 2 (6.9%) in group 2 ( P = NS), and the clinical recovery period decreased from 7 days to 4.5 days ( P = .05). During a mean follow-up of 26.7 months (range, 1-66 months) there were 5 repeat surgeries (9%) to treat late graft occlusion, establishing midterm primary and secondary patency rates of 89.3% and 91%, respectively. No aortic false aneurysms were detected, and no major amputations were performed. Conclusion These preliminary results assess the feasability and the safety of this minimally invasive video-assisted technique. A short period of postoperative recovery and good midterm patency rate are the two main benefits of this new surgical option.

Axillobifemoral bypass grafting

Axillo-femoral bypass (AxF) means connecting the axillar and femoral artery with the graft that is placed subcutaneously. Usually, this graft is connected with contralateral femoral artery via one accessory subcutaneous graft, and this connection is known as axillobifemoral bypass (AxFF). This extra-anatomic procedure is an alternative method to the standard reconstruction of aortoiliac region when there are contraindications for general or local reasons. The objective of this paper is to show early and late results of AxFF bypass grafting as well as to show the indications for AxFF bypass. The sample consisted of 37 patients. The procedure was performed in 28 patients who suffered from aortoiliac occlusive disease and who were at high risk due to the comorbidity--in one patient with the rupture of juxtarenal aneurysm of abdominal aorta; in five patients with aortoenteric fistula, in two patients with latrogenic lesion of abdominal aorta and in one female patient with anus preternaturalis definitivus who was treated for rectovaginal fistula. Donor's right axillary artery was used in 26 cases (70.3%), and donor's left axillary artery was used in 9 cases (29.7%). Dacron graft was used in 34 patients and Polytetrafluoroethlylene graft was used in three patients. Simultaneously, profundoplastic was done in four patients and femoro-popliteal bypass was performed in three patients. In five patients who suffered from aortoenteric fistula, simultaneous intervention of gastrointerstinal system has been done. Chi2 test was used for statistical evaluation and life table method was used for verification of late graft patency. The rate of early postoperative mortality was 13.5%. The causes of death were: sepsis--1, MOFS--3, and infarct myocardium--1. The mean follow up period was 40.1 months, ranging from six months to 17 years. During the follow up period, an early graft thrombosis was identified in two and late graft occlusion was reported in four patients. As the cause of occlusion, the progression of occlusive disease of receptive artery was identified in three patients, while anastomotic neointimae hyperplasia of recipient artery was identified in one patient. Three patients died during the follow up period. As the cause of death, CVI was reported in two patients and malignancy of the urinary tract was found in one patient. The other complications were--artery angulation on the level of proximal anastomosis in one patient (Figure 1), false aneurysm in one patient, perigraft seroma in one patient and graft infection in three patients. Life table method has shown that cumulative rate of late graft patency is 80.39% after five years (Graph 1). Our results were analyzed and compared with the results of the study on 283 patients who had undergone aortobifemoral bypass (AFF) operation due to the aortoiliac occlusive disease. This study was completed in 1995 (18). The results showed that there was no statistically significant differences between AxFF and AFF group (p > 0.05), considering early mortality rate and late graft patency (Graph 2). The review of mortality and late patency rate after AxFF bypass grafting in a world well known studies has shown the similar results (Table 1). CONCLUSION The authors suggest that axilobifemoral bypass is indicated when there are contraindications or difficulties to perform anatomic reconstruction due to the abdomen condition (infection, adhesion, comorbidity) as well as in high risk patients with low life expectancy.

One hundred twenty-five concomitant endovascular and open procedures for lower extremity arterial disease.

Although the results of staged endovascular and open surgical reconstructions have been well documented, the safety and efficacy of concomitant procedures in the operating room are less well defined. Suboptimal performance of endovascular procedures in an operative setting, or inappropriate reliance on endovascular techniques, might theoretically compromise graft patency. We questioned whether late graft thrombosis is frequently attributable to failure at the endovascularly treated site in this setting. Between May 1, 1993, and June 30, 2001, we performed 125 concomitant endovascular and open arterial reconstructions (73 primary reconstructions, 52 graft revisions) in 106 patients. Endovascular techniques were used to treat inflow lesions in 72 cases, outflow lesions in 14 cases, both in four cases, and the graft itself in 35 cases. Fifty-five iliac, 18 femoral, 13 popliteal, six tibial, and 35 graft lesions were treated. For primary bypasses, 33 were to the popliteal level (21 prosthetic, 12 autogenous), 19 were to the tibial or pedal arteries (16 autogenous, three prosthetic or composite), and 12 were to the femoral arteries (one autogenous, 11 prosthetic). Nine patch angioplasties (eight femoral, one popliteal) were performed. For graft revisions, endovascular intervention was for inflow in 13 cases, outflow in three cases, both in one case, and of the graft itself in 35 cases. Surgical revisions involved segmental grafts in 33 cases, patch angioplasty in 18 cases, and both in one case. In the primary group, the initial technical success rate of the endovascular procedure was 93% (68/73), with five patients needing open conversion. The 30-day mortality rate was 1.4%, and the morbidity rate was 11.0%. Of the 19 grafts in the primary group that occluded during the follow-up period (mean, 11.9 months), five thromboses could possibly be attributed to failure at the endovascular site. In the revision group, the initial technical success rate of the endovascular procedure was 88% (46/52), with six patients undergoing conversion to open procedure. The 30-day mortality rate was 0%, and the morbidity rate was 15.4%. Of 22 late graft occlusions in the revision group, only three were attributed to failure at the endovascular site. This largest report to date of concomitant lower extremity endovascular and open revascularization procedures shows the approach to be safe. Few late graft occlusions were attributable to failure at the endovascularly treated site. The concomitant approach offers the efficiency and convenience of single stage therapy and allows immediate treatment for inadequate endovascular results or their complications and potential cost savings.

An Experimental Model of Coronary Anastomosis without Suturing

Objective The aim of the study is to explore the feasibility and mid-term patency of an easier anastomotic technique for Minimally Invasive Direct Coronary Bypass Grafting (MIDCAB). Methods Eight mongrel dogs (±15 kg) underwent direct anastomosis between the left internal thoracic artery (LITA) and the left anterior descending coronary artery (LAD) via inferior sternotomy on the beating heart. After positioning the graft, the distal part of the LAD was opened to allow retrograde filling of the LITA-graft. The anastomosis was secured by the use of biological glue (BtoGlue, Cryolife, Marietta, GA, USA). No intravascular suture material was used. Ischemic time averaged 6 min. The proximal LAD was occluded upstream the arteriotomy. All survivors were angiographically controlled for patency after 6–8 weeks. Consequently, four dogs were sacrificed after 6 weeks and the remaining after 3 months for anatomo-pathological and histological examination by light and electron microscopy of the anastomotic site. Results All procedures were successful except for one animal that died of uncontrollable bleeding at the anastomotic site. Another sustained post-operative transmural anterior myocardial infarction due to a late graft occlusion. All angiographically controlled grafts were patent with two vascular strings near the anastomotic site. Histology showed early macrophage infiltration into the glue. At post-mortem examination, new endothelialization was noticed in 80% of the cases. However, ultrastructural examination detected marked differences in endothelial fibroblastic lining compared to normal histology. Conclusions Good mid-term permeability of the LITA grafts was observed in this new anastomotic technique for MIDCAB in the canine model. Although neo-endothelialization was present in most cases, ultrastructural differences were noticed after 3 months in the neointima compared to normal.

An experimental model of coronary anastomosis without suturing

Objective: The aim of the study is to explore the feasibility and mid-term patency of an easier anastomotic technique for Minimally Invasive Direct Coronary Bypass Grafting (MIDCAB). Methods: Eight mongrel dogs (±15 kg) underwent direct anastomosis between the left internal thoracic artery (LITA) and the left anterior descending coronary artery (LAD) via inferior sternotomy on the beating heart. After positioning the graft, the distal part of the LAD was opened to allow retrograde filling of the LITA-graft. The anastomosis was secured by the use of biological glue (BioGlue, Cryolife, Marietta, GA, USA). No intravascular suture material was used. Ischemic time averaged 6 min. The proximal LAD was occluded upstream the arteriotomy. All survivors were angiographically controlled for patency after 6–8 weeks. Consequently, four dogs were sacrificed after 6 weeks and the remaining after 3 months for anatomo-pathological and histological examination by light and electron microscopy of the anastomotic site. Results: All procedures were successful except for one animal that died of uncontrollable bleeding at the anastomotic site. Another sustained post-operative transmural anterior myocardial infarction due to a late graft occlusion. All angiographically controlled grafts were patent with two vascular strings near the anastomotic site. Histology showed early macrophage infiltration into the glue. At post-mortem examination, new endothelialization was noticed in 80% of the cases. However, ultrastructural examination detected marked differences in endothelial fibroblastic lining compared to normal histology. Conclusions: Good mid-term permeability of the LITA grafts was observed in this new anastomotic technique for MIDCAB in the canine model. Although neo-endothelialization was present in most cases, ultrastructural differences were noticed after 3 months in the neo-intima compared to normal.

Aortomonoiliac stent-grafts for abdominal aortic aneurysm repair: association with iliofemoral crossover grafts.

To analyze the outcome of endovascular exclusion of abdominal aortic aneurysm (AAA) using aortomonoiliac stent-grafts. Fifty-seven consecutive patients (49 men; median age 70, range 56-89) with AAA >5 cm were treated in a 6-year period with the conical ELLA stent-graft. Forty-two (73.9%) patients were classified ASA (American Society of Anesthesiologists) IV and 6 as ASA V. In the majority of cases, the implantation procedure featured device delivery through the external iliac artery, transrenal placement of a bare stent in selected cases, and an iliofemoral crossover graft through a prevesical tunnel. Successful deployment was achieved in 56 (98.2%) patients. Mean time to discharge was 8.7 days (range 2-125). Two patients died in the 30-day period. Nine endoleaks occurred in 8 (14%) patients; 4 required further intervention. Mean follow-up was 35.3 months (range 1-66), during which 5 patients died from unrelated causes. No late endoleak, graft occlusion, device twisting/migration, or aneurysm rupture was observed. No correlation between type I endoleaks and unfavorable proximal neck or iliac artery anatomical characteristics could be found. Primary technical and clinical success rates were 86.0% and 94.7%, respectively. In this approach, the crossover graft remains in a retropubic space and consequently does not have all the disadvantages of a subcutaneously placed prosthesis. The results achieved in this group of high-risk patients support recommendation of this technique as a simple and safe alternative to bifurcated systems.

Left main trunk ostial stenosis and aortic incompetence in Takayasu's arteritis

A 41-year-old woman with recent onset of heart failure and angina due to aortic valve incompetence and critical left coronary ostium stenosis in the setting of Takayasu's arteritis is reported. The patient was successfully surgically treated by aortic valve replacement and coronary artery bypass with saphenous vein graft, showing a cardiac event-free 17 months follow-up. Takayasu's arteritis must be included among the possible causes of coronary artery disease and aortic valve incompetence in young female patients. Although chronic inflammation of the aortic wall may result in late graft occlusion, surgical therapy is effective for short and mid-term clinical improvement.

Abdominal aortic aneurysm repair with the Zenith stent graft: Short to midterm results

Purpose: The purpose of this study was to assess the short-term and mid-term results of endovascular aneurysm repair with the Zenith stent graft in a single-center prospective study. Method: Between October 1998 and July 2001, we used the Zenith stent graft for elective endovascular aneurysm repair in 116 patients, six of whom were women. The mean age was 75 years, and the mean aneurysm diameter was 60.3 ± 8.8 mm. Stent grafts were oversized 10% to 20% relative to computed tomographic (CT) scan-based diameter measurements. All repairs were performed in the operating room through surgically exposed femoral arteries. The results were assessed before discharge with three-phase, contrast-enhanced CT scan and plain abdominal radiograph. These studies were repeated at 1, 6, 12, and 24 months after operation. Follow-up periods ranged from 1 to 34 months. Results: No failed insertions and no conversions to open surgery occurred. The diameter of the main body of the stent graft was 28 mm or more in 73 patients (63%). Additional stents were inserted during surgery to treat kinking in eight patients (6.9%) and renal artery encroachment in two patients (1.7%). Mean fluoroscopy time was 35.1 ± 18.3 minutes, contrast load was 146 ± 53 mL (350 mg/mL), and estimated blood loss was 249 ± 407 mL. The major complication rate was 9.5%, and the minor complication rate was 10.3%. The perioperative complications were myocardial infarction in four patients, arrythmia in four patients, and pulmonary embolism, renal failure, stroke, small bowel obstruction, femoral stenosis, digital embolism, and graft limb thrombosis in one patient each. All 116 patients went home from the hospital, but one patient died 2 weeks later of a combination of pulmonary embolism and myocardial infarction. Endoleak was seen on the first CT scan in 16 patients (15%); 15 were type II, and one was type III. No endoleaks of type I or IV were seen. Additional interventions were performed for each of the following conditions: type II endoleak (n = 4), type III endoleak (n = 1), femoral clamp injury (n = 1), renal artery stenosis (n = 1), and graft limb occlusion (n = 1). One patient had acute aneurysm dilatation and rupture caused by a type II endoleak through the inferior mesenteric artery 6 months after stent graft implantation. No cases were seen of late graft occlusion, stent graft migration, stent fracture, barb fracture, or secondary endoleak. Conclusion: The Zenith device is safe, versatile, and effective in the short to medium term. Most patients need wide stent grafts (≥28 mm proximally and ≥16 mm distally) to achieve 10% to 20% oversizing to prevent type I endoleak. (J Vasc Surg 2002;36:217-25.)

Initial experience with minimally invasive in situ bypass procedure with blind valvulotomy.

The in situ vein (ISV) bypass is uniquely suited to technical modifications designed to reduce the wound morbidity of infrainguinal revascularization. A technique of "blind" valvulotomy and selective vein branch ligation was used, and a preliminary study was performed to assess safety and efficacy. From November 1998 to July 2001, all patients for infrainguinal bypass procedures underwent evaluation for inclusion in the study. Thirty-five patients underwent ISV bypass procedures with an expandable, self-centering valvulotome (ESV). Intraoperative selection of veins suitable for the study was assisted with venography and duplex scanning. The ISV bypass procedures were performed with initial groin and distal incisions, with smaller incisions to ligate significant arteriovenous fistulae (AVF). Duplex graft scanning was performed at routine intervals after surgery. Thirty-seven ISV grafts were performed from the common femoral artery to the popliteal (n = 14), tibial (n = 20), and dorsalis pedis (n = 3) arteries. In 35 cases (95%), a full-length incision was avoided. With ESV, all valves in 34 cases (92%) were effectively lysed. Proximal extension of the distal incision was performed in four cases (10.8%). The mean number of incisions per case was 3.1 +/- 1.7. One graft failed within 30 days (2.7%), with successful revision. During the early follow-up period (9.9 +/- 7.3 months; range, 1 to 33 months), 44% of residual AVF closed spontaneously (15 of 34 AVF; 16 patients) and two anastomotic stenoses and two symptomatic AVF were corrected surgically. Four late graft occlusions occurred, with a 1-year cumulative primary patency rate of 77% and a secondary patency rate of 92%. Blind valvulotomy with ESV facilitates safe and effective minimally invasive ISV bypass. Resultant graft patency rates appear comparable with results with open techniques. This preliminary experience warrants further study to refine patient selection criteria and operative technique and to better clarify the natural history of residual AVF.

Results of Lower Limb Revascularization from the Descending Thoracic Aorta

The aim of this retrospective study was to substantiate our results of lower limb revascularizations from the descending thoracic aorta. From November 1984 to November 1994, we used bypass grafting from the descending thoracic aorta to revascularize 69 lower limbs in 36 patients, 34 men and 2 women, whose mean age was 61.8 years. Patients were divided into two groups. Group I (primary indications) included 10 patients who had not had any prior lower limb arterial reconstruction. Group II (secondary indications) consisted of 26 patients who had had a prior arterial reconstruction that was either occluded or complicated. There were three early graft occlusions, all of them successfully treated. Complete flaccid, paraplegia occurred in one patient. Five patients presented with one or several late graft occlusions. Two patients had to undergo below-knee amputation, bilateral in one patient. Routine late control of the repair was performed by CT scanning, at a mean interval of 50.8 months. The good results recorded for bypasses revascularizing lower limbs from the descending thoracic aorta make this technique a satisfactory alternative when the abdominal aorta cannot be used.

Replacement of the inferior vena cava for malignancy: An update

Objectives: Resection and replacement of the inferior vena cava (IVC) to remove malignant disease is a formidable procedure. Since our initial report with IVC replacement for malignancy, we have maintained an aggressive approach to these patients. The purpose of this review is to update our experience with regard to patient selection, operative technique, and early and late outcome.Methods: All patients who had IVC replacement for primary (n = 2) or secondary (n = 27) vena cava tumors from April 1990 to May 1999 were reviewed. Tumor location and type, clinical presentation, the segment of IVC replaced, graft patency, performance status of the patient, and tumor recurrence and survival data were collected. Late follow-up data were available for all but one patient. The IVC was replaced in 28 patients with large diameter (≥14 mm) externally supported ePTFE grafts and with a panel graft of superficial femoral vein in the other. Three patients had a femoral arteriovenous fistula. Graft patency was determined before hospital dismissal and in follow-up by vena cavography, computed tomography, ultrasonography, or magnetic resonance imaging.Results: There were 18 women and 11 men, with a mean age of 53.1 years (range, 16–88 years). Over one half of patients had symptoms from their tumor. IVC replacement was at the suprarenal segment in 15 patients, of whom 13 had concomitant major hepatic resection, at the infrarenal segment in 10, at both caval segments in three, and at the renal vein confluence in one. There were two early deaths (6.9%). One patient died intraoperatively of coagulopathy during liver resection and suprarenal IVC replacement. The other death occurred 4 months postoperatively, from multisystem organ failure that resulted in graft infection and occlusion. Twelve patients had one or more major complications — cardiopulmonary problems in five; bleeding in five; chylous ascites or large pleural effusions in two patients each; and lower extremity edema with tibial vein thrombosis in one. The mean follow-up was 2.8 years (range, 2.7 months to 6.3 years). Two late graft occlusions occurred: one at 7.5 months, the other, from tumor recurrence, at 6.3 years. There have been no other late graft-related complications. All 11 late deaths were caused by the progression of malignant disease. Of 16 survivors, 12 have no evidence of disease and four have either regional or distant metastatic recurrence. Initial postoperative performance status was good or excellent for most survivors.Conclusions: Aggressive surgical management may offer the only chance for cure or palliation of symptoms for patients with primary or secondary IVC tumors. Our experience suggests that vena cava replacement may be performed safely with low graft-related morbidity and good patency in carefully selected patients.