Dacron or PTFE for above-knee femoropopliteal bypass. a multicenter randomised study.

OBJECTIVES: To compare polytetrafluorethylene (PTFE) and polyester grafts (Dacron) for above knee femoropopliteal bypass. DESIGN: Multicenter randomised clinical trial. MATERIAL AND METHODS: 427 patients were randomised between 6mm Dacron (Uni-Graft, B. Braun Melsungen AG, 34212 Melsungen, Germany) and PTFE (Goretex, W. L. Gore & Ass. Inc., Newark DE 19711, USA) above-knee femoropopliteal bypass grafts within 13 centres in Denmark (n=261), Norway (n=113) & Finland (n=53) between 1993 and 1998. Fourteen (3%) patients were excluded, leaving 413 patients with 208 Dacron and 205 PTFE grafts for analysis. Age, gender, indication (claudication: 65%), run-off (2 or 3 vessels: 76%), diabetes (17%) and hypertension (31%) as well as cerebrovascular (9%) and cardiac (33%) risks were evenly distributed. Patients were followed postoperatively at 1, 12 and 24 months. Patency assessment was based on ankle-brachial pressures or imaging in case of doubt. RESULTS: The two-year primary patency rates for Dacron and PTFE were 70% and 57% (p=0.02), whereas the secondary patency rates were 76% and 65% (p=0.04), respectively. Primary patency at two years was significantly influenced by the number of patent crural vessels (two or three 67%, one 50%, p=0.01). Amputations at two years, major in 4% and minor in 3%, 30-days mortality and complications (wound infections: 3% and other wound complications: 13%) occurred equally frequent in both groups. At two years, patients treated for critical limb ischemia had a major amputation more often than patients operated on for intermittent claudication, 10 and 3 respectively (p=0.003), and had higher mortality rates, 20% and 8% respectively (p=0.001). CONCLUSION: This trial confirms that Dacron is at least as durable as PTFE for above-knee bypass procedures, and might even be superior.

Fluoropolymer-coated dacron versus PTFE grafts for femorofemoral crossover bypass: randomised trial.

OBJECTIVES: To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery. DESIGN: A randomised multicentre clinical trial comparing two vascular grafts with participation of 10 departments of vascular surgery in Denmark, Sweden and Norway. PATIENTS AND METHODS: 198 patients were randomised to PTFE (n=107) or fluoropolymer-coated Dacron grafts (n=91), 63% underwent surgery for claudication, 27% for ischaemic rest pain and 10% for tissue loss. The median follow-up time was 24 months (IQR 19-26 months). RESULTS: The primary patency rate of the two grafts was similar (log rank test: p=0.35). The primary patency rates (95% CI) for coated Dacron and PTFE grafts were 92% (86-98) and 94% (89-99) at 12 months and 87% (74-95) and 93% (87-99) at 24 months, respectively. CONCLUSION: In patients with unilateral iliac artery disease not amenable to angioplasty, the femoral-femoral bypass is durable and effective. No difference in patency was found between the two graft materials (fluoropolymer coated Dacron and PTFE).

Does an adjuvant AV-fistula improve the patency of a femorocrural PTFE bypass with distal vein cuff in critical leg ischaemia?--a prospective randomised multicentre trial.

INTRODUCTION: A lack of suitable veins can cause serious problems when attempting to revascularise critically ischaemic legs. Prosthetic grafts have much worse patency in the femocrural position, despite the use of distal anastomotic cuffs. The use of adjuvant AV-fistula at the distal anastomosis should increase the graft flow above the thrombotic threshold velocity and thus increase prosthetic graft patency. AIM: The aim of the study was to evaluate the benefit of an adjuvant AV-fistula on the patency of a femorocrural PTFE bypass with a distal vein cuff. MATERIALS AND METHODS: This prospective randomised multicentre trial was conducted in four centres. A total of 59 patients with critical leg ischaemia and no suitable veins for grafting were randomised to receive a femocrural PTFE bypass and distal vein cuff, with or without an adjuvant AV-fistula. Thirty-one patients were randomised to the AV-fistula group (AVFG) and 28 to the control group (CG). Six patients were lost to follow-up during the 2-year study time. RESULTS: There were six immediate occlusions in each treatment group, but half of these were saved by re-operation. The mean postoperative ankle-brachial index (ABI) was 0.85 in the AVFG and 0.94 in the CG. The primary and secondary patency rate at 2 years was 29 and 40% for the AVFG and 36 and 40% for the CG (NS). Leg salvage at 2 years was 65 and 68%, respectively (NS). CONCLUSION: Adjuvant AV-fistula does not improve the patency of a femorocrural PTFE bypass with a distal vein cuff.

[Hemorrhagic diarrhea with competing etiologies]. / Blodig diaré med konkurrerende aetiologi.

A case history of a 41-year-old woman with bloody diarrhoea is described. A right-sided hemicolectomy was performed and histological findings showed pseudomembranous colitis. The woman was infected with verotoxin-producing E. coli O103:H2. She had taken an overdose of ergotamine and was using a contraceptive containing oestrogen. Each of these have previously been described as being the cause of bloody diarrhoea, but we suggest the combination as the aetiology in the present case.

The importance of complete follow-up for results after femoro-infrapopliteal vascular surgery.

OBJECTIVES: The aim of this study was to assess the reliability of patency rates calculated on basis of data from a standard vascular registry. DESIGN AND SETTING: Since 1989, all patients undergoing infrainguinal bypass procedures have been offered a standard follow-up programme at 3 month intervals and all data have been recorded prospectively in a vascular registry. As part of a randomised trial on adjuvant medication in femorocrural bypass surgery, 102 patients, operated on between 1990 and 1992 were independently and simultaneously monitored. This subgroup was examined at 3 and 12 months postoperatively and 100% follow-up was obtained. After completion of the trial we calculated the patency and survival rates using life-table methods and compared the results based on the vascular registry with those achieved in the clinical trial. RESULTS: Comparing the results from the two databases revealed a marked discrepancy between the calculated figures: primary (68% in the registry and 52% in the trial) and secondary patency rates (90% vs. 63%), limb survival (97% vs. 77% as well as patients survival rates (95% vs. 85%). The differences could be explained by a substantial number of patients being lost to follow-up according to the vascular registry database and the fact that these patients turned out to have a significantly increased rate of graft thrombosis, limb amputation and death, respectively. CONCLUSIONS: Life-table statistics may inadvertently become unreliable if a large proportion of patients is lost to follow-up, since failure to examine the patient for any reason may be related to the patients health. In addition to the number of patients at risk, it is suggested, that life-table plots should be supplemented with information on the number of patients lost to follow-up.

[Surgery for abdominal aortic aneurysm. What is an acceptable complications rate?]. / Kirurgi for abdominale aortaaneurismer. Hva er akseptabel komplikasjonsfrekvens?

At the annual meeting of the Vascular Section of the Scandinavian Surgical Society in 1993 it was decided to discuss standards for quality in vascular surgery. This article is discussing operations for abdominal aortic aneurysms with special reference to early mortality and complications like graft infection and aortoenteric fistula. The discussion is based on national vascular registers and investigations on vascular surgical activity in the Scandinavian countries. In addition, a survey of the literature is given. Although these data should be regarded as a guide-line only, we feel that one should try to keep the 30 day mortality following elective resection for asymptomatic abdominal aortic aneurysm below 5-7 per cent. A mortality less than 50-60 per cent following operation for ruptured aneurysm may be regarded as reasonable. Patient-selection regarding age, concomitant disease etc. could significantly influence these results, and should be taken into consideration when comparison between different series is made. Graft infection is a serious complication and if the frequency is higher than 2 per cent, or there is an accumulation of graft infections in a vascular centre, the hospital routines should be reviewed carefully. The occurrence of infection is higher following operations for ruptured aneurysms than following elective operations. Early operations for haemorrhage and early occlusion should be below 5-6 per cent. Some authors have shown a correlation between the volume of operation, postoperative mortality and the frequency of complications. We therefore think that it might be reasonable to suggest that at least patients who have concomitant diseases like serious coronary heart disease or renal insufficiency should be operated on in vascular centres.(ABSTRACT TRUNCATED AT 250 WORDS)

[Excimer laser-assisted balloon angioplasty of the femoro-popliteal segment]. / Excimer-laser-assisteret ballonangioplastik af det femoropopliteale segment.

In the Department of Vascular Surgery RK, The University Hospital in Copenhagen, the authors have treated 16 patients with ischaemia in the lower limb by means of laser-assisted balloon angioplasty. A pulsed ultraviolet excimer-laser was employed. It proved possible to break down the occluding arterial lesion in 12 patients (75%). In one patient, this was not followed-up by balloon angioplasty and, in another patient, the reconstruction closed on the first day after operation. The primary success of the procedure, defined as breaking down of the occlusion with the laser-catheter followed by balloon angioplasty and an increase in the ankle/brachial index of greater than 15%, was found to be 10/16 or 62%. The remaining four patients, in whom it did not prove possible to break down the arterial lesion with laser, were treated by means of conventional vascular surgical reconstruction. On follow-up examination after an average of nine months, nine out of the ten patients (90%) still had a patent reconstruction after laser-assisted balloon angioplasty. This new endovascular laser-procedure appears to be suitable for selected patients, but must be assessed more meticulously before it is possible to determine its future placing in the vascular surgical therapeutic armamentarium.

Gentamycin beads in the treatment of localised vascular graft infection--long term results in 17 cases.

Seventeen patients were treated by the implantation of gentamycin beads for localised Szilagyi type III prosthetic graft infection. Three patients had a pan prosthetic infection and half of the remaining patients were cured, but three of these died from other causes within 3 months. The mean observation time of the four survivors was 20 months (7-39 months). One of the seven patients, in whom the gentamycin beads failed, died of infection, giving a total mortality rate of 6% (1.5-29%). The remaining patients were cured after resection of the infected segment of the prosthesis at a mean follow-up of 22 months (8-37 months).

[Femoro-popliteal bypass surgery in Denmark 1983-1987]. / Femoro-popliteal bypass-kirurgi i Danmark 1983-1987.

In a retrospective study of femoro-popliteal bypass surgery in Denmark during the period 1983 to 1987, a total of 1,532 operations were performed. Approximately 2/3 of the patients were operated upon for limb salvage, the remainder for severe disabling claudication. The perioperative lethality was below two per cent in all departments. Early occlusion rate was found to be between 21 and 11 per cent, leading to major amputation in about half of the patients.

Albumin administration and acute phase proteins in abdominal vascular surgery. A randomised study.

Previous studies suggest that supplementary exogenous albumin may adversely affect hepatic protein synthesis. To test this, 18 patients undergoing elective abdominal aortic surgery were studied. Based on randomisation, nine patients received an average of 53.3 g albumin as part of blood replacement therapy, followed by 20 g albumin daily for the first three postoperative days. The remainder received no albumin. Sequential changes in plasma concentrations of albumin, transferrin, C-reactive protein, orosomucoid, fibrinogen and immunoglobulin G and A were monitored for the first week, as were changes in plasma volume and plasma colloid osmotic pressure. Supplementary albumin caused significant differences in plasma colloid osmotic pressure on postoperative days 1, 2 and 4 (p less than 0.01) and in albumin concentration at all postoperative measurement times (p less than 0.01). Plasma volumes did not differ between the groups. All protein fractions other than albumin showed identical curve sequences and peak concentrations. The significant decrease (p less than 0.01) in concentration of all proteins except albumin of the albumin group was quantitatively explained by unreplaced plasma loss. The study rules out consequences of clinical importance of albumin supplementation on hepatic protein synthesis.

"Femoro-distal bypass--a worthwhile procedure?".

Infrapopliteal vascular reconstruction was undertaken in 63 patients with limb threatening ischaemia. Graft materials used were reversed autogenous saphenous vein in 33 patients, umbilical vein in 23 patients, composites of saphenous and umbilical vein in six patients, and a Solcograft in one patient. At the end of the first month 13 grafts were non-functioning, and eight of these patients had an amputation performed. Cumulative 3-year limb salvage and patency rates were 69% and 35%, respectively. Cumulative patency rates of saphenous and umbilical vein grafts were equal, and neither the indication for operation nor the preoperative ankle-arm pressure index correlated to graft failure. In total, twenty-two major amputations were performed, 16 below or through the knee, and six above-knee. The conclusion is that vascular reconstructive surgery for limb threatening distal disease is a valuable procedure.

Changes in extracellular sodium content after elective abdominal vascular surgery.

To investigate the possible occurrence of extra- to intracellular sodium shift in elective surgery, whole-body extracellular sodium mass/1.73 m2 was determined as the product of plasma sodium concentration and the volume of distribution of polyfructosan-S/1.73 m2 in 53 patients before abdominal aortic surgery and on the first and fourth postoperative days. The patients were divided into four groups, receiving stepwise increasing amounts of sodium. After surgery the extracellular sodium mass was lower than expected from the sum of preoperative value and cumulative sodium balance/1.73 m2. This deficit in extracellular sodium mass showed linear correlation with the sodium balance on postoperative day 1. On day 4 the mean deficits in extracellular sodium mass ranged from 227 to 291 mmol/1.73 m2 in the four groups, and the corresponding cumulative sodium balances from 179 to 528 mmol/1.73 m2. Net shift of sodium into the cells may explain the extracellular sodium deficit.

Aortobifemoral bypass with autogenous saphenous vein in treatment of paninfected aortic bifurcation graft.

An alternative method is presented in which aortobifemoral bypass with autogenous great saphenous vein is implanted after excision of previously inserted synthetic aortobifemoral grafts because of prosthetic "paninfection." The procedure was followed in five patients; one death occurred and the remaining four patients recovered completely from graft infection. Only in one case did saphenous vein thrombosis occur. These results are encouraging considering the high mortality rates following the previously available methods of management.

The importance of plasma colloid osmotic pressure for interstitial fluid volume and fluid balance after elective abdominal vascular surgery.

The relationships between plasma colloid osmotic pressure (COPp) and interstitial fluid volume (IFV) as well as postoperative fluid balance were investigated in a prospective study involving 53 patients undergoing elective abdominal aortic reconstruction. The patients were divided into four groups according to pre- and postoperative blood replacement and fluid therapy programs whereby a continuum of postoperative COPp-values between 33 and 16 mmHg was obtained. Measurements were done before the operation and on days 1 and 4 after surgery. After surgery, COPp below 20 mmHg led to increased IFV. On day 1, COPp was linearly correlated to the total amount of fluid retained during the day of operation. A positive fluid balance of 3 L on this day ensured unchanged extracellular fluid volume (ECV). Of the 3 L, 1.5 L was insensible water loss and 1.5 L had moved into the cells. On day 4 after surgery, COPp below 22 mmHg was associated with increased plasma volume. The authors suggest that COPp be maintained above 20 mmHg after major surgery, and positive fluid balance should not exceed 5 L during the day of operation.

Increased glomerular filtration rate in patients after reconstructive surgery on the abdominal aorta.

Fifty-three patients undergoing elective reconstructive surgery on the abdominal aorta were included in a prospective study to obtain information on postoperative glomerular filtration rate (GFR) in relation to increased fluid and sodium intake and decreased plasma colloid osmotic pressure (COP). GFR, extracellular fluid volume (ECV) and COP were measured before operation and on the first and fourth day after surgery. GFR and ECV were measured by means of the single injection residue detection method using the inulin analogue polyfructosan-S as marker. The compiled GFR values increased from 92.3 to 103.7 ml min-1 1.73 m-2 (P less than 0.002) on the first day, and to 105.3 ml min-1 1.73 m-2 (P less than 0.001) on the fourth day after surgery. Concomitantly, ECV increased from 8.9 litres 1.73 m-2 (P less than 0.025) respectively. Positive linear correlation was found on the first postoperative day between GFR per 1.73 m2 and ECV per 1.73 m2 (r = 0.33, P less than 0.05) and between GFR per 1.73 m2 and extracellular sodium content per 1.73 m2 (r = 0.38, P less than 0.01). COP was not correlated to GFR per 1.73 m2. The postoperative increase in GFR found in this study is most likely to be the result of increased ECV and renal plasma flow. Whether other factors are also involved remains unknown.

Sequential changes in circulating total protein and albumin masses after abdominal vascular surgery.

Sequential changes in total circulating protein (TCP) and total circulating albumin (TCA) masses after different blood replacement regimens were investigated in a prospective study involving 40 patients undergoing reconstructive abdominal aortic surgery. Group I (13 patients) had 80 gm of albumin during operation and 60 gm of albumin during the following 3 days. Blood loss was replaced milliliter for milliliter by whole blood. Group II (14 patients) had the same blood substitution but no albumin. In group III (13 patients), 800 ml of blood loss was replaced by salt water. Maximum decrease in TCP (group II: 17%, group III: 29%) was found 4 hours after the operation. On postoperative day 1, protein mobilization to plasma equalling 10% of TCP had occurred. On day 4, TCP and plasma colloid osmotic pressure had not changed in group I, indicating an unchanged TCA/TCP ratio. In groups II and III, a significant decrease in TCP was followed by complete recovery of TCP. This also entailed a decrease in the TCA/TCP ratio, indicating an enhanced synthesis of acute-phase proteins. Based on these findings, a depression of globulin synthesis by supplemental albumin administration is proposed.