Current results of open revascularization for chronic mesenteric ischemia: a standard for comparison

OBJECTIVE

Questions remain concerning the optimal site of graft origin and the extent of revascularization necessary to achieve excellent results for chronic mesenteric ischemia (CMI). Endovascular therapy also is performed for CMI. These factors prompted us to review our results to provide a current standard.

METHODS

Ninety-eight patients who underwent operation for CMI from 1989 to 1998 were reviewed. Patients with acute ischemia and arcuate ligament syndrome were excluded.

RESULTS

Seventy-six women (78%) and 22 men (22%), with an average age of 66 years (range, 36 to 87 years), participated in the study. Abdominal pain was present in 95 patients (97%), and weight loss in 92 patients (94%). The superior mesenteric artery was severely diseased (70% to 99% stenosis or occlusion) in 90 patients (92%), the celiac artery in 81 patients (83%), and both arteries in 76 patients (78%). Bypass grafts were performed in 91 patients (93%), 77 antegrade and 14 retrograde. Of the other seven patients, five had endarterectomies, one reimplantation, and one patch angioplasty. Multivessel reconstruction was performed in 79 patients (81%), and single-vessel reconstruction in 19 (19%). Twelve patients had concomitant aortic reconstruction. Three early graft thromboses were seen. Five hospital deaths occurred (5.1%); one case had concomitant aortic reconstruction (1/12 versus 4/86; P = not significant). All five patients who died were older than 70 years (5/41 versus 0/57; P =.011). The median follow-up period was 1.9 years (range, 0 to 9.6 years). Follow-up was complete in all survivors. The 1-year, 5-year, and 8-year survival rates were 83%, 63%, and 55%, respectively. These rates were worse than the rates of the age-matched/gender-matched control subjects (P <.001). Survival was worse in patients greater than 70 years of age (P =.0013). Survival was unaffected by the number of vessels revascularized. The patients with retrograde grafts had decreased median survival rates (4.0 versus 5.7 years; P =.026), but they were older (75 versus 65 years; P =.0013). The 1-year and 5-year symptom-free survival rates were 95% and 92%, respectively. Symptoms recurred in six patients (6%): four had recurrent stenosis/occlusion and two had patent grafts. Symptom-free survival was unaffected by the number of vessels revascularized or by graft orientation.

CONCLUSION

Operation for CMI was successful for most patients, with low operative mortality and excellent long-term relief of symptoms. Selective concomitant aortic procedures did not increase mortality rates. The rate of symptomatic recurrences was not different for single-vessel versus multiple-vessel reconstructions or for antegrade versus retrograde grafts. Patients older than 70 years had increased operative mortality and decreased survival rates. Endovascular therapy may be appropriate for this subset of patients.

[Manifestations of atherosclerosis in various vascular regions. Similarities and differences regarding epidemiology, etiology and prognosis]

Pathologic studies have demonstrated that atherosclerosis involves the whole arterial vessel tree. In the Framingham study, cardiovascular risk factors could be defined with different prognostic value for the development of atherosclerosis in various vascular regions. The prognosis of patients with atherosclerosis in coronary, carotid or leg arteries is worse compared to a normal population. Moreover, patients with symptomatic lesions in one vascular bed often have additional asymptomatic atherosclerotic lesions in other vascular regions. Patients with atherosclerosis in multiple vascular regions have a worse prognosis than patients with atherosclerosis in one vascular bed only. In a study of 804 patients, we could show a significantly higher incidence of cardiovascular events (death, myocardial infarction, stroke) in patients with coronary artery disease (CAD) and additional lesions in peripheral arteries (leg, carotid) during a 3.2-year follow-up compared to those with CAD only. Local and systemic inflammatory processes in the arterial vessel wall are considered to play an important role with regard to plaque instability. It has been suggested, that besides the symptomatic atherosclerotic lesion, multiple stable or unstable lesions are present in the whole arterial vessel tree predicting the patient's prognosis. Chronic infections with multiple pathogens ("concept of infectious burden") probably play an important role by triggering these inflammatory processes. Therefore, systemic therapeutic regimes are necessary for the treatment of patients with atherosclerosis. The platelet aggregation inhibitors improve the prognosis of patients with atherosclerosis in all vascular areas. Another important therapeutic regime is the use of statins, which seem to be not only effective in lipid lowering but also in plaque stabilization.

[Influence of etiology and morphology of traumatic vascular injuries on outcome, risk of amputation and mortality]

In a retrospective trial 159 vascular injuries in 149 patients were registered between 1987-1996. Extremity vessels were injured in 76% of the cases. The same incidence was observed in blunt and penetrating mechanisms. Blunt vascular injuries were associated with an higher rate of live threatening organ damage, longer times of ischaemia (6.5 versus 3.0 h) and an higher mortality (9.7 versus 20.3%) than penetrating injuries. We have found an increased mortality rate in all cases with concomitant trauma of CNS, chest, abdomen or bones. The overall amputation rate in all peripheral vascular injuries has been 22.6%. The functional outcome has been reduced by nerve lesions, amputation and the sequelae of fractures.

Contemporary management of acute mesenteric ischemia: Factors associated with survival

PURPOSE

Acute mesenteric ischemia (AMI) is a morbid condition with a difficult diagnosis and a high rate of complications, which is associated with a high mortality rate. For the evaluation of the results of current management and the examination of factors associated with survival, we reviewed our experience.

METHODS

The clinical data of all the patients who underwent operation for AMI between January 1, 1990, and December 31, 1999, were retrospectively reviewed, clinical outcome was recorded, and factors associated with survival rate were analyzed.

RESULTS

Fifty-eight patients (22 men and 36 women; mean age, 67 years; age range, 35 to 96 years) underwent study. The cause of AMI was embolism in 16 patients (28%), thrombosis in 37 patients (64%), and nonocclusive mesenteric ischemia (NMI) in five patients (8.6%). Abdominal pain was the most frequent presenting symptom (95%). Twenty-five patients (43%) had previous symptoms of chronic mesenteric ischemia. All the patients underwent abdominal exploration, preceded with arteriography in 47 (81%) and with endovascular treatment in eight. Open mesenteric revascularization was performed in 43 patients (bypass grafting, n = 22; thromboembolectomy, n = 19; patch angioplasty, n = 11; endarterectomy, n = 5; reimplantation, n = 2). Thirty-one patients (53%) needed bowel resection at the first operation. Twenty-three patients underwent second-look procedures, 11 patients underwent bowel resections (repeat resection, n = 9), and three patients underwent exploration only. The 30-day mortality rate was 32%. The rate was 31% in patients with embolism, 32% in patients with thrombosis, and 80% in patients with NMI. Multiorgan failure (n = 18 patients) was the most frequent cause of death. The cumulative survival rates at 90 days, at 1 year, and at 3 years were 59%, 43%, and 32%, respectively, which was lower than the rate of a Midwestern white control population (P <.001). Six of the 16 late deaths (38%) occurred because of complications of mesenteric ischemia. Age less than 60 years (P <.003) and bowel resection (P =.03) were associated with improved survival rates.

CONCLUSION

The contemporary management of AMI with revascularization with open surgical techniques, resection of nonviable bowel, and liberal use of second-look procedures results in the early survival of two thirds of the patients with embolism and thrombosis. Older patients, those who did not undergo bowel resection, and those with NMI have the highest mortality rates. The long-term survival rate remains dismal. Timely revascularization in patients who are symptomatic with chronic mesenteric ischemia should be considered to decrease the high mortality rate of AMI.

Long-term outcome after mesenteric artery reconstruction: a 37-year experience

PURPOSE

The purpose of this study was the definition of the late results and determining factors after mesenteric artery reconstruction (MAR) for atherosclerotic mesenteric ischemia.

METHODS

A retrospective review identified 48 consecutive patients (66 arteries) who underwent MAR for acute mesenteric ischemia (AMI) of nonembolic origin (n = 23; 12 with and 11 without prior symptoms) and chronic mesenteric ischemia (CMI; n = 25) from 1963 to 2000 in a tertiary care referral center. The 29 women (60%) and the 19 men (40%) had a mean age of 64 years (range, 40 to 87 years). The operative procedures consisted of bypass grafting in 36 arteries (AMI, 12; CMI, 24), local endarterectomy (LEA) in 16 arteries (AMI, 9; CMI 7), and transaortic endarterectomy (TAE) in 14 arteries (AMI, 4; CMI, 10). The follow-up of the 34 survivors was complete in all but four patients and averaged 5.3 years (range, 30 days to 36 years). Radiographic documentation of vessel/graft patency was obtained in 33 of 34 survivors.

RESULTS

Single-vessel revascularization was performed more frequently in the AMI group than in the CMI group (91% versus 48%; P =.001). The perioperative (<30 days) mortality rate in the AMI group was 52% (12 of 23 cases) as compared with 0 of 25 cases in the CMI group (P <.001). Bowel infarction was the cause of nine deaths. Major complications occurred in 60% of the cases. Fifteen late graft failures occurred, for a cumulative patency rate of 57% at 5 years and 46% at 10 years. TAE was associated with improved patency rates as compared with LEA (TAE versus LEA; P =.002). Symptomatic recurrences developed in eight patients, all involving superior mesenteric artery thrombosis (P <.001). The freedom-from-recurrence rates in the survivors were 79% at 5 years and 59% at 10 years. The late survival rates were 54% and 20% at 5 and 10 years, respectively. With the exclusion of perioperative deaths, the probability of long-term survival was 77% at 5 years and 29% at 10 years and did not differ between AMI and CMI.

CONCLUSION

Although MAR for CMI carries a low mortality rate, AMI remains a lethal and frequently unheralded problem. Long-term patency and symptom-free survival can be expected after successful MAR for AMI and is comparable with those rates achieved after MAR for CMI. The patency of the SMA is important in the prevention of symptomatic recurrences. Elective MAR is indicated in patients with CMI and warrants long-term surveillance.

Sex-related differences in outcome after vascular interventions for lower limb ischemia

OBJECTIVE

The purpose of this study was to investigate sex-related differences in outcome, defined as amputation rate and survival in patients treated for lower limb ischemia.

MATERIAL AND METHOD

Age, sex, and type of procedure for all patients undergoing vascular interventions for lower limb ischemia in Stockholm, Sweden, from 1970 to 1994, were obtained from the National Board of Health and Welfare. All patients who underwent amputation after treatment were analyzed separately. Data on deceased patients were extracted from the cause-of-death register.

RESULTS

Women had lower survival rates than men at 30 days and 1 and 5 years after operation (89% vs 92%, 75% vs 80%, and 50% vs 55%; P <.001). In the multivariate analysis of risk factors for death during the whole study period, increasing age, calendar year (1980 to 1989), and male sex were significant risk factors (P <.001). The percentage of women who underwent amputation after treatment was comparable with the percentage of men who underwent amputation (11.4% vs 10.2%, P =.075). The multivariate analysis identified increased age and calendar year (1985 to 1994) as important risk factors for amputation (P <.001). Female sex was not found to increase the risk for amputation. Patients who underwent amputation were older than patients with intact limbs (73 vs 68 years, P <.001). The highest percentage of patients who underwent amputation was found among those treated with femorodistal bypass (20%, P =.001).

CONCLUSIONS

Female sex is not an important risk factor for poor outcome after treatment for lower limb ischemia, when their increased age has been accounted for. These results imply that we should continue to consider age and type of procedure when estimating outcome, and women should not be refused an intervention on a sex-related basis. We should possibly be more selective toward men considering their higher mortality rates.

Shank vessel injuries

The management of lower extremity vascular injuries has undergone dramatic changes over the last century. With the optimal management of femoral and popliteal injuries established, controversy still exists with respect to management of vascular injuries below the popliteal fossa, in the shank arterial vessels. These injuries are uncommon, often limb threatening, and usually require complex management decisions. Incidence of shank vessel injuries, imaging studies required for accurate and expedient diagnosis, determinants influencing the decision for repair or amputation, and details of techniques in surgical intervention are discussed.

The influence of gender difference on the outcomes of infrainguinal bypass for critical limb ischaemia in Chinese patients

PURPOSE

to investigate the influence of gender difference on the outcomes of infrainguinal bypass operations performed in Chinese patients with critical limb ischaemia.

METHODS

we prospectively studied the results of 191 consecutive infrainguinal bypass operations (98 men, 93 women) for critical lower limb ischaemia in Chinese patients.

RESULTS

the women were older than men (median 75 vs 70 years, p=0.001) and cigarette smoking was commoner in men (83% vs 37% p<0.001). The calibre of run-off arteries at the level of distal anastomosis was smaller in women (median 2.5 mm vs 2.0 mm, p=0.03). The 30-day mortality was 3% (five men vs one woman, p=0.09) and early graft failure occurred in 19 patients (12 women vs seven men, p=0.28). At 3 months limb loss occurred in 16 (10 women vs six men, p=0.35) patients. Survival (38% vs 60% at 4 years, p=0.12) was similar in men and women. However, women suffered from poorer primary (33% vs 49% at 3 years, p=0.03) secondary graft patency rates (35% vs 64% at 3 years, p=0.02) than men. Limb survival rate in two groups (75% vs 85% at 4 years, p=0.18) was comparable.

CONCLUSION

following infrainguinal bypass for critical limb ischaemia, early results were similar in both gender groups. In the long-term, women patients suffered from significantly higher graft failure rate. However, their long-term survival and limb salvage rate remained comparable to those of men.

Cholesterol reduction in patients with lower limb atherosclerotic disease

Patients with peripheral arterial disease (PAD) have a 2-3 times increased risk of death and in the most severe stage, critical peripheral ischaemia, the mortality rate is around 50% within 4-5. This poor survival rate is due to concomitant coronary and cerebrovascular atherosclerotic disease. Among the major risk factors for atherosclerosis are dyslipidaemia, smoking, hypertension and diabetes. Large randomised trials have shown that dyslipidaemia is easily modifiable in both patients with and without established coronary artery disease, with significant reductions in cardiovascular morbidity and mortality. Although none of these trials directly measured peripheral vascular status, there is every indication that conclusions submitted for patients with ischaemic heart disease can be translated to patients with peripheral vascular disease. The object of this review was therefore to divulge current evidence available supporting active treatment of dyslipidaemia in patients with peripheral vascular disease.

Early results of a prospective randomized trial of spliced vein versus polytetrafluoroethylene graft with a distal vein cuff for limb-threatening ischemia

OBJECTIVE

Single-piece vein remains the conduit of choice in patients who need bypass grafting for limb salvage. When this option is not available, two of the remaining options are prosthetic bypass graft or several segments of vein spliced together. In this study, we compare spliced vein bypass grafting versus polytetrafluoroethylene grafting with a distal vein cuff in patients with limb-threatening ischemia.

METHODS

Between 1996 and 2000, 39 bypass grafting procedures in 36 patients were performed for limb-threatening ischemia. These procedures were prospectively randomized to either spliced vein bypass grafting (spliced group, 19 bypass grafts) or polytetrafluoroethylene grafting with a distal vein cuff (cuff group, 20 bypass grafts). All the patients in the cuff group underwent anticoagulation therapy with warfarin sodium after surgery. The inclusion criteria included: no single-piece vein option for bypass grafting, adequate vein for splice, no composite sequential option, and limb-threatening ischemia. The demographics were similar between the two groups.

RESULTS

The primary patency rate at 2 years was 44% and 49% for the spliced and cuff groups, respectively. In the spliced group, seven of 19 bypass grafts underwent revision in the follow-up period, and two of 20 cuffed bypass grafts were successfully revised. The secondary patency rate was 87% and 59% (P <.05), with limb salvage rates of 94% and 85% for spliced and cuff groups, respectively. Four patients in the spliced vein group needed reoperation for wound complications related to vein harvest. One polytetrafluoroethylene graft needed removal for infection. Two early mortalities occurred in the spliced group, one from myocardial infarction and one from stroke. The overall survival rate at 2 years between the two groups was 67% and 100% for the spliced and cuff groups, respectively (P <.05).

CONCLUSION

Although this is a preliminary report, it appears that both spliced vein bypass grafting and polytetrafluoroethylene bypass grafting with a distal vein cuff produce acceptable limb salvage rates. The secondary patency rate for spliced vein is better, but these bypass grafts more often need revision or reoperation for wound complications.

Endovascular surgery for chronic limb ischaemia. Factors predicting immediate outcome on the basis of a nationwide vascular registry

PURPOSE

To evaluate the early results of endovascular treatment of chronic limb ischemia and the factors influencing outcome.

METHODS

The 5,575 endovascular procedures entered into the national vascular registry in 1991-1994 were reviewed retrospectively. Indication was claudication in 3,873 and chronic critical ischemia (CLI) in 1,702 procedures. In CLI most patients were women and older, with a higher proportion of diabetes mellitus, renal insufficiency and coronary heart disease than in claudication group although the incidence of smoking and hyperlipidaemia was lower. 60.2% of the procedures were performed in femoropopliteal arteries, 24.9% in iliac arteries and 14.9% in infrapopliteal arteries. The follow-up was 30 days.

RESULTS

In the claudication group there was clinical improvement in 2,719 (82.8%) and in the CLI group in 851 (70.9%) of patients. Patency was better in the claudication than in CLI group, 94.6% vs. 89.0% respectively. There was hemodynamic improvement, i.e. improvement of the ankle-brachial index of more than 0.15 in 1,680 (58.2%) patients with claudication and in 437 (59.7%) with CLI. In a logistic regression model diabetes mellitus and renal insufficiency increased the relative risk of amputations and mortality in CLI group, whereas, incidence of amputations was lower in patients with hyperlipidaemia. In claudication group femoropopliteal arteries had an adverse effect on patency.

CONCLUSION

The clinical characteristics of the groups may explain some of the outcome differences. Angioplasty is recommended to be used in the femoropopliteal arteries if the symptoms are severe and in CLI group with diabetes and renal failure only in selected cases.

Tumor necrosis factor alpha, but not Fas, mediates hepatocellular apoptosis in the murine ischemic liver

BACKGROUND & AIMS

Apoptosis of hepatocytes is a central feature of ischemic injury in the liver. The aim of this study was to identify extracellular inducers of apoptosis in the murine ischemic liver.

METHODS

Involvement of tumor necrosis factor (TNF)-alpha and Fas signaling was evaluated using various knockout mice (TNF-receptor 1 [TNF-R1]-/-, Fas[lpr]-/-, and Fas ligand[gld]-/-) and wild-type mice pretreated with pentoxifylline, an inhibitor of TNF-alpha synthesis.

RESULTS

Expression of TNF-alpha was increased after ischemia and reperfusion in wild-type mice and TNF-R1-deficient mice when compared with sham-operated animals. Pentoxifylline prevented up-regulation of TNF-alpha expression. Inhibition of TNF-alpha resulted in significant decrease of serum aspartate aminotransferase levels and prolonged animal survival. Markers of apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining, cytochrome C release, and caspase 3 activity) were consistently decreased, and animal survival was prolonged after blocking TNF-alpha. In contrast, inhibition of Fas signaling did not alter parameters of tissue injury or apoptosis, and animal survival remained unchanged.

CONCLUSIONS

We identify TNF-alpha as a crucial inducer of apoptotic cell death in the ischemic liver. A role for Fas could not be identified. These findings may lead to novel strategies to prevent ischemic injury of the liver.

[Lipid lowering treatment of patients with atherosclerotic disease of the lower extremities]

Patients with critical peripheral ischaemia have a significant mortality rate of up to 50% within 4-5 years of surgical vascular reconstruction. This poor survival rate is due to concomitant coronary and cerebrovascular atherosclerotic disease. Large randomised trials have shown that dyslipidaemia is easily modifiable in patients both with and without established coronary artery disease, with significant reductions in cardiovascular morbidity and mortality. Although none of these trials directly measured peripheral vascular status, there is every indication that conclusions submitted for patients with ischaemic heart disease can be translated to patients with peripheral arterial disease (PAD). The object of this review was therefore to divulge the current evidence available, which supports active treatment of dyslipidaemia in patients with PAD.

Selected contribution: Effects of gender on reduced-size liver ischemia and reperfusion injury

Hepatic resection with concomitant periods of ischemia and reperfusion (I/R) is a common occurrence in resectional surgery as well as reduced-size liver transplantation (e.g., split liver or living donor transplantation). However, the I/R induced by these types of surgical manipulations may impair liver regeneration, ultimately leading to liver failure. The objectives of the study were to develop a murine model of reduced-size liver I/R and assess the role of gender in this model of hepatocellular injury. We found that 100% of female mice survived the surgery indefinitely, whereas all male mice had greater initial liver injury and died within 5 days after surgery. The protective effect observed in females appeared to be due to ovarian 17beta-estradiol, as ovariectomy of females or administration of a selective estrogen antagonist to female mice resulted in enhanced liver injury and greater mortality following reduced-size liver I/R. Conversely, 17beta-estradiol-treated male mice exhibited less hepatocellular damage and survived indefinitely. Taken together, these data demonstrate an estrogen-mediated protective pathway(s) that limits or attenuates hepatocellular injury induced by reduced-size liver I/R.

Tibial bypass using complex autologous conduit: patency and limb salvage

Over an 8-year period, we performed 93 lower extremity bypasses using complex autologous conduits, which included (1) contralateral greater saphenous vein (GSV), (2) composite GSV, (3) superficial femoral vein, (4) lesser saphenous vein, (5) cephalic or basilic veins, and (6) composite-sequential (PTFE and vein) grafts. These grafts represented 16% of all infrainguinal bypasses during this period, and all grafts were performed to treat limb-threatening ischemia. Survival, patency, and limb salvage were examined by the life-table method. Primary graft patency was 46 and 38% at 3 and 5 years. Assisted-primary patency was 62 and 59%, and secondary graft patency rates were 68 and 64% at 3 and 5 years. Twenty-nine bypasses (31%) required revision to restore or maintain patency. The 3-year limb salvage rate was significantly better when revision was performed for graft stenosis than for graft thrombosis (90% vs. 46%, p < 0.05). Overall limb salvage rate was 73% at 5 years. The mortality rate was 5.4% and the 5-year survival was 51%. Complex autologous tibial bypasses provided acceptable long-term limb salvage in patients with severe ischemia and inadequate ipsilateral GSV. The increased operating time and complexity required did not produce prohibitive operative risks. Postoperative graft surveillance in these complex vein bypasses allowed revision in many cases before graft occlusion occurred and significantly improved long-term limb salvage.

Early results of retrograde transpopliteal angioplasty of iliofemoral lesions

PURPOSE

To assess whether the retrograde transpopliteal approach is a safe, practical and effective alternative to femoral puncture for percutaneous transluminal angioplasty (PTA).

METHODS

Forty PTAs in 38 patients were evaluated. Intentional subintimal recanalization was performed in 13 limbs. Ultrasound evaluation of the popliteal fossa was carried out 30 min and 24 hr postprocedurally in the first 10 patients to exclude local complications. All patients had a follow-up of at least 6 weeks.

RESULTS

The indication for PTA was critical ischemia in seven limbs and disabling claudication in the remainder. Stenoses (single or multiple) were present in 24 and occlusion in 15. The superficial femoral artery (SFA) was the commonest segment affected (36) followed by common femoral artery (CFA) in four and iliac artery in four. Technical success was achieved in 38 of 39 limbs where angioplasty was carried out. In one limb no lesion was found. Immediate complications were distal embolization in two and thrombosis in one. None of these required immediate surgery. There were no puncture site hematomas or popliteal arteriovenous fistulae. Symptomatic patency at 6 weeks was 85%. Further reconstructive surgery was required in three limbs and amputation in two.

CONCLUSION

The transpopliteal approach has a high technical success rate and a low complication rate with a potential to develop into an outpatient procedure. It should be considered for flush SFA occlusions or iliac disease with tandem CFA/SFA disease where the contralateral femoral approach is often technically difficult.

Comparison of the mortality between ischemia and frequent premature ventricular contractions on an exercise test

Ischemia on an exercise test (ET) is a known risk factor for cardiovascular mortality. However, the magnitude of risk of frequent premature ventricular contractions (PVCs) on ET is often overlooked. This analysis reveals that the quantitative additional mortality risk on ET presented by frequent PVCs is similar to ischemia.

Safe upper limit of intermittent hepatic inflow occlusion for liver resection in cirrhotic rats

AIM: To evaluate the effects of varying ischemic durations on cirrhotic liver and to determine the safe upper limit of repeated intermittent hepatic inflow occlusion.

METHODS: Hepatic ischemia in cirrhotic rats was induced by clamping the common pedicle of left and median lobes after non-ischemic lobes resection. The cirrhotic rats were divided into six groups according to the duration and form of vascular clamping: sham occlusion (SO), intermittent occlusion for 10 (IO-10), 15 (IO-15), 20 (IO-20) and 30 (IO-30) minutes with 5 minutes of reflow and continuous occlusion for 60 minutes (CO-60). All animals received a total duration of 60 minutes of hepatic inflow occlusion. Liver viability was investigated in relation of hepatic adenylate energy charge (EC). Triphenyltetrazollum chloride (TTC) reduction activities were assayed to qualitatively evaluate the degree of irreversible hepatocellular injury. The biochemical and morphological changes were also assessed and a 7-day mortality was observed.

RESULTS: At 60 min after reperfusion following a total of 60 min of hepatic inflow occlusion, EC values in IO-10 (0.749 ± 0.012) and IO-15 (0.699 ± 0.002) groups were rapidly restored to that in SO group (0.748 ± 0.016), TTC reduction activities remained in high levels (0.144 ± 0.002 mg/mg protein, 0.139 ± 0.003 mg/mg protein and 0.121 ± 0.003 mg/mg protein in SO, IO-10 and IO-15 groups, respectively). But in IO-20 and IO-30 groups, EC levels were partly restored (0.457 ± 0.023 and 0.534 ± 0.027) accompanying with a significantly decreased TTC reduction activities (0.070 ± 0.005 mg/mg protein and 0.061 ± 0.003 mg/mg protein). No recovery in EC values (0.228 ± 0.004) and a progressive decrease in TTC reduction activities (0.033 ± 0.002 mg/mg protein) were shown in CO-60 group. Although not significantly different, the activities of the serum aspartate aminotransferase (AST) on the third postoperative day (POD₃) and P OD₇ and of the serum alanine aminotransferase (ALT) on POD₃ in CO-60 group remained higher than that in intermittent occlusion groups. Moreover, a 60% animal mortality rate and more severe morphological alterations were also shown in CO-60 group.

CONCLUSION: Hepatic inflow occlusion during 60 min for liver resection in cirrhotic rats resulted in less hepatocellular injury when occlusion was intermittent rather than continuous. Each period of 15 minutes was the safe upper limit of repeated intermittent vascular occlusion that the cirrhotic liver could tolerate without undergoing irreversible hepatocellular injury.

Duplex scanning allows selective use of arteriography in the management of patients with severe lower leg arterial disease

PURPOSE

Until April 1997 we routinely performed intra-arterial digital subtraction angiography (iaDSA) in all patients with severe lower leg ischemia requiring intervention. After a comparative study of duplex scanning (DS), pulsegenerated runoff, and iaDSA of the lower leg arteries, we postulated that management could be based on DS/pulse-generated runoff in 59% of patients. We prospectively evaluated the safety of such a noninvasive workup strategy.

METHODS

All consecutive patients referred with severe lower leg ischemia between April 1997 and September 1998 were eligible. Management was based on DS with iaDSA being performed only on indication. Complications within 30 days and 12- and 24-month patency, survival, and limb salvage rates were recorded and compared with historical controls.

RESULTS

A total of 125 limbs in 114 patients were evaluated (74% rest pain or tissue loss). In 97 (78%) of 125 limbs, management was based on DS. It comprised conservative treatment (n = 33, 0% after iaDSA), percutaneous transluminal angioplasty (n = 25, 16% iaDSA), femoropopliteal bypass graft (n = 29, 17% iaDSA), femorotibial bypass graft (n = 29, 62% iaDSA), and other surgical procedures (n = 8, 4% iaDSA). Overall, the mortality within 30 days was 4% (5/114), and 2-year survival was 83%. Two-year primary and secondary patency and limb salvage rates were 75%, 93%, and 93% after a femoropopliteal bypass operation, respectively. One-year primary and secondary patency and limb salvage rates were 35%, 73%, and 74%, respectively, after a femorocrural bypass operation. There were no differences in patient characteristics, indication for specific treatment, and immediate and intermediate term outcome between the study and reference population.

CONCLUSION

In a vascular unit with wide expertise in DS of the lower leg arteries, management of patients with severe lower leg ischemia can be based on DS in most patients without negative effects on clinical outcome within 30 days and at 2-years' follow-up.

Galectin-3 protects human breast carcinoma cells against nitric oxide-induced apoptosis: implication of galectin-3 function during metastasis

Galectin-3 is a beta-galactoside-binding protein which regulates many biological processes including cell adhesion, migration, cell growth, tumor progression, metastasis, and apoptosis. Although the exact function of galectin-3 in cancer development is unclear, galectin-3 expression is associated with neoplastic progression and metastatic potential. Since studies have suggested that tumor cell survival in microcirculation determines the metastatic outcome, we examined the effect of galectin-3 overexpression in human breast carcinoma cell survival using the liver ischemia/reperfusion metastasis model. While the majority of control cells died by hepatic ischemia/reoxygenation, nearly all of galectin-3 overexpressing cells survived. We showed that galectin-3 inhibits nitrogen free radical-mediated apoptosis, one of the major death pathways induced during hepatic ischemia/reperfusion. Galectin-3 inhibition of apoptosis involved protection of mitochondrial integrity, inhibition of cytochrome c release and caspase activation. Taking these results together with the previous observation that galectin-3 inhibits apoptosis induced by loss of cell adhesion, we propose that galectin-3 is a critical determinant for anchorage-independent and free radical-resistant cell survival during metastasis.

Prospective comparison of arm veins and greater saphenous veins as infrageniculate bypass grafts

OBJECTIVES

to compare arm and saphenous veins for infrageniculate bypass grafting.

DESIGN

prospective non-randomised study.

MATERIALS

two hundred patients, of which 197 had ischaemic tissue loss or rest pain.

METHODS

two hundred and eleven infrageniculate vein bypass procedures using 176 greater saphenous veins and 35 arm veins.

RESULTS

the cumulative primary graft patency rate at 1-month and 2 years was 80% and 61% for saphenous vein and 89% and 42% for arm vein. The corresponding rates for secondary patency were 84.5% and 68%, and 91% and 57%, respectively. These results corresponded to a relative risk of secondary failure of 1.53 (95% CI 0.71, 3.31) for arm vein grafts. In subgroup analyses, this estimate was 0.93 and 2.1 for primary vs secondary bypasses and 0.38 and 2.06 for single-vein vs spliced-vein bypasses. Among arm veins, cephalic vein grafts performed better than basilic vein grafts. Early mortality was 14% for arm vein and 10% for saphenous vein.

CONCLUSION

in the setting of infrageniculate bypass grafting, arm vein grafts are not equivalent to greater saphenous vein grafts, but contribute importantly to a policy of using autologous veins. The possibility of equivalence remains for the arm vein graft that uses a cephalic vein or is a primary procedure.

Lipoprotein (a) level and mortality in patients with critical lower limb ischaemia

OBJECTIVE

to investigate if serum lipoprotein (a) level is a predictor of survival in patients with lower limb atherosclerotic occlusive disease.

DESIGN

prospective follow up study.

METHODS

demographic, biochemical and disease variables were collected prospectively in 441 patients with lower limb arterial occlusive disease. Survival data were obtained at a mean follow up of 44 months, and significant risk factors identified by the life table method and multivariate Cox regression analysis.

RESULTS

the cumulative survival for all patients at three and five years was 79% and 63%. Lipoprotein (a) level was the only significant independent biochemical predictor for all deaths and cardiorespiratory deaths on multivariate analysis, along with age, diabetes mellitus, renal impairment, cardiac diseases and major amputation. An elevated Lipoprotein(a) level of >24 mg/dl incurred a 107% and 45% increase in mortality at three and five years respectively. The higher mortality associated with elevated Lipoprotein (a) was particularly evident in patients with critical ischemia, in whom three and five year survival was reduced from 85% to 63% and 67% to 53% (p=0.0064). In claudicants a survival discrepancy was manifested only after five years (73% vs 62%), and the overall association did not reach statistic significance (p=0.52).

CONCLUSIONS

lipoprotein (a) level is a reliable biochemical marker for survival in patients with critical ischemia where traditional atherosclerosis risk factors were prevalent.

Infrainguinal bypass grafting in patients with end-stage renal disease: improving outcomes?

OBJECTIVE

This study was undertaken to examine recent trends in the outcomes of patients with end-stage renal disease (ESRD) undergoing infrainguinal bypass grafting (IBG) with autogenous vein.

METHODS

A retrospective analysis of all IBGs performed on patients with ESRD at a single tertiary care institution during the interval 1993 to 1999 was undertaken. The comparison groups consisted of concurrent series of patients with elevated creatinine (creatinine level > 1.2 mg/dL) and patients with normal renal function undergoing IBG. Procedural variables, angiographic runoff scores, and extent of tissue necrosis at presentation were correlated with outcome. Categoric parameters were compared with chi(2) analysis; rates were computed with life-table analysis.

RESULTS

Of an overall cohort of 622 IBGs performed during this interval, 78 IBGs (12.5%) were performed on 60 patients with ESRD, with a perioperative mortality rate of 1.3% that was comparable to controls. All reconstructions in the ESRD cohort were for limb salvage indications. Four-year survival, primary, assisted primary, and secondary patency rates for the ESRD group were 51% +/- 9%, 60% +/- 11%, 86% +/- 5%, and 86% +/- 5%, respectively; these were not statistically different from the control groups. Limb salvage in the ESRD group was 77% +/- 6% at 4 years and was significantly less then either the elevated creatinine (92% +/- 4%; P <.02) or the normal renal function group (90% +/- 2%: P <.02). Of 16 amputations in the ESRD group, nine were performed in limbs with patent grafts. The only absolute predictor of limb loss despite a patent graft was the presence of a heel ulcer more than 4 cm in diameter. Age, runoff score of the International Society for Cardiovascular Surgery/Society for Vascular Surgery, isolated tibial bypass graft, and location of distal anastomosis were not predictive of hemodynamic failure.

CONCLUSIONS

Patients with ESRD constitute an increasing proportion of patients undergoing IBG in a tertiary care setting. Four-year survival, perioperative mortality, and graft patency rates are similar to patients with normal renal function and support an aggressive approach to this population. Major limb amputation despite a patent graft remains a problem of unique frequency in patients with ESRD. Adequate predictors of hemodynamic failure of IBG in this group do not exist, although a heel ulcer more than 4 cm may indicate an unsalvageable foot.

Thrombolysis for native arterial occlusions of the lower extremities: clinical outcome and cost

INTRODUCTION

Intra-arterial thrombolysis is commonly used as the initial treatment of acute or subacute lower extremity ischemia.

METHODS

To evaluate the efficacy and cost of thrombolysis, we retrospectively analyzed 100 consecutive cases (87 patients) in which intra-arterial lysis (urokinase) was used as the initial treatment for native arterial lower extremity occlusive disease. The mean age of patients was 67 years, 57% of the patients were male, and preexisting peripheral vascular disease was present in 74%. Presenting symptoms were limb-threatening ischemia (53%) and claudication (47%). Acute symptoms (< 2 weeks' duration) were present in 48%.

RESULTS

The 30-day morbidity rate was 31%, and four patients died. Complications were significant bleeding (23%), ischemic stroke (1%), and renal failure with (2%) and without (2%) dialysis. Concomitant angioplasty was performed in 63%. Complete or significant lysis as demonstrated with angiography was achieved in 75% of iliac, 58% of femoropopliteal, and 41% of crural vessels (P <.001). Within 30 days of lysis, 9% of patients underwent major amputation and 20% surgical revascularization (in 3 patients the extent of revascularization was lessened by the lytic therapy). Amputation-free survival was 83% and 75% at 6 months and 2 years, respectively. Relief of ischemia (defined as relief of claudication or limb salvage without major surgical intervention) was achieved in only 70% and 43% of patients at 30 days and 2 years, respectively (Kaplan-Meier analysis; mean follow-up, 31 months). Patients with aortoiliac disease had significantly better outcomes than those with infrainguinal disease (P =.03). Duration or type of presenting symptoms did not predict outcome. The cost of the initial hospitalization per patient for thrombolysis was $18,490.

CONCLUSION

Thrombolysis can be as or more costly than surgery and is associated with a suboptimal outcome in a significant number of patients. These data lead us to caution against a uniform policy of initial thrombolysis for patients who present with lower extremity ischemia.

Attenuation of liver and lung injury after hepatic ischemia and reperfusion by a cytokine-suppressive agent, FR167653

BACKGROUND

Hepatic ischemia/reperfusion (I/R) injury is an important clinical problem and leads to the release of the proinflammatory cytokines, TNF-alpha and IL-1. These cytokines play important roles in the induction of polymorphonuclear neutrophil (PMN) activation and infiltration, and induce not only localized hepatic injury but also remote organ injury, especially pulmonary injury. Using a total hepatic ischemia model in rats, we tested our hypothesis that suppression of TNF-alpha and IL-1 by FR167653 ameliorates I/R injury in the liver and lung.

METHODS

Male Wistar rats, weighing 240-280 g, were divided into 3 groups, an FR group, a control group and a sham group. In the FR group, FR167653 (1 mg/kg/h) was administered continuously to the animals for 30 min prior to the onset of ischemia and for 2 h after reperfusion. The control group received normal saline. A porto-systemic shunt was placed between the cecal branch of the portal vein and the jugular vein, and total hepatic ischemia was produced for 90 min. The sham group was treated with placement of the porto-systemic shunt only. The 1-week survival rate, liver enzyme activity, hepatic tissue blood flow (HTBF), cytokine mRNA expression, myeloperoxidase (MPO) activity and histological results were studied.

RESULTS

The 1-week survival rate and HTBF were significantly higher in the FR group than in the control group. Serum AST, ALT, and LDH levels were significantly lower in the FR group at 30 min, 1 h and 3 h after reperfusion. MPO levels in liver and lung tissue were also significantly lower in the FR group. The expression of IL-1beta mRNA remarkably decreased up to 6 h after reperfusion in the FR group.

CONCLUSIONS

We concluded that the inflammatory cytokines, IL-1beta, play important roles in hepatic I/R injury. FR167653 might ameliorate I/R injury and be useful in liver surgery with ischemia.