Editor's Choice - Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

OBJECTIVE

The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR).

METHODS

This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests.

RESULTS

The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively).

CONCLUSION

In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

DCD donor hemodynamics as predictor of outcome after kidney transplantation

Insufficient hemodynamics during agonal phase-ie, the period between withdrawal of life-sustaining treatment and circulatory arrest-in Maastricht category III circulatory-death donors (DCD) potentially exacerbate ischemia/reperfusion injury. We included 409 Dutch adult recipients of DCD donor kidneys transplanted between 2006 and 2014. Peripheral oxygen saturation (SpO2-with pulse oximetry at the fingertip) and systolic blood pressure (SBP-with arterial catheter) were measured during agonal phase, and were dichotomized into minutes of SpO2 > 60% or SpO2 < 60%, and minutes of SBP > 80 mmHg or SBP < 80 mmHg. Outcome measures were and primary non-function (PNF), delayed graft function (DGF), and three-year graft survival. Primary non-function (PNF) rate was 6.6%, delayed graft function (DGF) rate was 67%, and graft survival at three years was 76%. Longer periods of agonal phase (median 16 min [IQR 11-23]) contributed significantly to an increased risk of DGF (P = .012), but not to PNF (P = .071) and graft failure (P = .528). Multiple logistic regression analysis showed that an increase from 7 to 20 minutes in period of SBP < 80 mmHg was associated with 2.19 times the odds (95% CI 1.08-4.46, P = .030) for DGF. In conclusion, duration of agonal phase is associated with early transplant outcome. SBP < 80 mmHg during agonal phase shows a better discrimination for transplant outcome than SpO2 < 60% does.

Early Conversion to Prednisolone/Everolimus as an Alternative Weaning Regimen Associates With Beneficial Renal Transplant Histology and Function: The Randomized-Controlled MECANO Trial

In renal transplantation, use of calcineurin inhibitors (CNIs) is associated with nephrotoxicity and immunosuppression with malignancies and infections. This trial aimed to minimize CNI exposure and total immunosuppression while maintaining efficacy. We performed a randomized controlled, open-label multicenter trial with early cyclosporine A (CsA) elimination. Patients started with basiliximab, prednisolone (P), mycophenolate sodium (MPS), and CsA. At 6 months, immunosuppression was tapered to P/CsA, P/MPS, or P/everolimus (EVL). Primary outcomes were renal fibrosis and inflammation. Secondary outcomes were estimated glomerular filtration rate (eGFR) and incidence of rejection at 24 months. The P/MPS arm was prematurely halted. The trial continued with P/CsA (N = 89) and P/EVL (N = 96). Interstitial fibrosis and inflammation were significantly decreased and the eGFR was significantly higher in the P/EVL arm. Cumulative rejection rates were 13% (P/EVL) and 19% (P/CsA), (p = 0.08). A post hoc analysis of HLA and donor-specific antibodies at 1 year after transplantation revealed no differences. An individualized immunosuppressive strategy of early CNI elimination to dual therapy with everolimus was associated with decreased allograft fibrosis, preserved allograft function, and good efficacy, but also with more serious adverse events and discontinuation. This can be a valuable alternative regimen in patients suffering from CNI toxicity.

Incidence, risk factors, and the impact of allograft pyelonephritis on renal allograft function

BACKGROUND

The impact of allograft pyelonephritis (AGPN) on renal allograft function is controversial. In this study, we evaluated the incidence, risk factors, and the impact of AGPN on renal allograft function.

METHODS

Retrospective cohort study in adult renal allograft recipients with 1-year follow-up after transplantation (Tx). Renal allograft function was evaluated by estimated glomerular filtration rate (eGFR) (by Modification of Diet in Renal Disease formula) and 24-h urine protein excretion.

RESULTS

A total of 431 renal allograft recipients were analyzed; 57 (13.2%) developed AGPN within 1 year after Tx. Median time between Tx and AGPN was 50 days. Risk factors for AGPN were the presence of a urological catheter (odds ratio [OR] = 18.93, 95% confidence interval [CI] = 8.00-44.81, P < 0.001) and preceding asymptomatic bacteriuria (ASB) (OR = 2.16, 95% CI = 1.20-3.90, P = 0.009). In 72.7%, the causative microorganism of ASB was identical to that of the succeeding AGPN episode. Multivariable linear regression analysis showed that experiencing AGPN did not decrease the eGFR (P = 0.61) nor did increased proteinuria (P = 0.29) 1 year after Tx. For the eGFR, an interaction was found between AGPN/bacteriuria (BU) and acute rejection (AR): the group experiencing BU preceding AR had significantly (P < 0.001) lower eGFR compared with the group that experienced only AR (21 mL/min/1.73 m² vs. 48 mL/min/1.73 m² ), as a result of increased prevalence of combined rejections within the BU group.

CONCLUSION

Indwelling urological catheters and preceding ASB are associated with developing AGPN. An incident of AGPN itself does not impair renal allograft function 1 year after Tx. However, a relevant interaction occurs between BU and AR, in which the sequence of occurrence of these 2 events synergistically impairs the eGFR.

First clinical experience with polysol solution: pilot study in living kidney transplantation

In this study, we assessed the safety of the new organ preservation solution polysol solution in the clinical setting of living kidney transplantation. We conducted a prospective pilot study in nine adult donor-recipient couples using polysol solution for washout and cold storage of kidney grafts. Adverse reactions possibly related to the use of polysol solution as well as renal function at 1, 6, and 12 months after transplantation were monitored. All living kidney transplantation performed in adults in our center within 2002 to 2008 using the University of Winconsin solution served as controls (n = 190). The use of polysol solution was associated with a higher acute rejection rate compared to University of Wisconsin solution at all time points. Also, antibody-mediated rejection occurred more frequently in the polysol group. Renal function at all time points was also comparable between the groups. This pilot study in living kidney transplantation is the first clinical study on the use of polysol solution. Although the study was not powered on the endpoint rejection, we observed a high number of acute rejection and antibody-mediated rejection episodes in recipients of polysol solution preserved grafts as compared to University of Wisconsin solution controls. As a consequence the study was terminated prematurely.

Chylous ascites after laparoscopic hand-assisted donor nephrectomy: Is it specific for the left-side?

We describe a case-report of a chylous ascites after laparoscopic donor nephrectomy, summarize the current literature, and hypothesize on the etiology of this complication.

Risk factors for delayed graft function after hand-assisted laparoscopic donor nephrectomy

BACKGROUND

Delayed graft function (DGF) has a negative effect on the results of living-donor kidney transplantation.

OBJECTIVE

To investigate potential risk factors for DGF.

METHODS

This prospective study included 200 consecutive living donors and their recipients between January 2002 and July 2007. Delayed graft function was defined as need for dialysis within the first postoperative week.

RESULTS

Delayed graft function was diagnosed in 12 patients (6%). Intraoperative complications occurred in 10 donors (5%), and postoperative complications in 24 donors (13.5%). One-year kidney graft survival with vs without DGF was 52% and 98%, respectively (P < .002). In donors, 2 univariate risk factors for DGF identified were lower counts per second at peak activity during scintigraphy, and multiple renal veins. In recipients, only 2 or more kidney transplantations and occurrence of an acute rejection episode were important factors. At multivariate analysis, increased risk of DGF was associated with the presence of multiple renal veins (odds ratio, 151.57; 95% confidence interval, 2.53-9093.86) and an acute rejection episode (odds ratio, 78.87; 95% confidence interval, 3.17-1959.62).

CONCLUSION

Hand-assisted laparoscopic donor nephrectomy is a safe procedure. The presence of multiple renal veins and occurrence of an acute rejection episode are independent risk factors for DGF.

Outcome of total parathyroidectomy and autotransplantation as treatment of secondary and tertiary hyperparathyroidism in children and adults

BACKGROUND

Treatment safety and effectiveness of total parathyroidectomy and autotransplantation for secondary and tertiary hyperparathyroidism have been extensively proven in adults; the evidence for children, however, is scarce. Children and adolescents cannot simply be seen as young adults in the case of chronic kidney disease and hyperparathyroidism. The aim of this retrospective study was therefore, to evaluate whether parathyroidectomy with forearm autograft is as effective and safe in children and adolescents as in adults.

METHODS

A group of 64 adults and 8 children and adolescents treated for secondary or tertiary hyperparathyroidism were retrieved from our database. The outcomes were compared on patient demographics, operation results, and blood parameters consisting of parathyroid hormone (PTH) and calcium levels. Our results were compared with all currently available articles on parathyroidectomy in children with secondary or tertiary hyperparathyroidism (n = 11).

RESULTS

For adults, preoperative mean serum calcium was 2.67 +/- 0.29 mmol/l and mean parathyroid hormone (PTH) level was 120 +/- 86 pmol/l. For children, preoperative mean serum calcium was 2.62 +/- 0.20 mmol/l and mean parathyroid hormone (PTH) level was 80 +/- 38 pmol/l. Postoperative calcium and parathyroid hormone levels for adults dropped to 2.39 +/- 0.23 mmol/l and 30 +/- 53 pmol/l, respectively. Postoperative calcium and parathyroid hormone levels for children dropped to 2.41 +/- 0.16 mmol/l and 26 +/- 33 pmol/l, respectively. The effectiveness of parathyroidectomy with autotransplantation was 75% in children and 72% in adults. Thus, effectiveness did not differ significantly between children and adults.

CONCLUSIONS

Combining the results of our own study with a literature review on pediatric parathyroidectomy, we conclude that parathyroidectomy and forearm autograft is as effective a treatment for secondary and tertiary hyperparathyroidism in children and adolescents as it is in adults.

Laparoscopic donor nephrectomy

Living donor nephrectomy has been developed and promoted as a method to address the shortfall in kidneys available for transplantation. The classical method to procure a kidney from a living donor is the open donor nephrectomy performed through a flank lumbotomy incision. However, this classical method has negative short- and long-term side effects for the donor. These disincentives are a drawback for possible donors to donate a kidney. Therefore, transplant surgeons were stimulated to develop new and less invasive techniques. In this review several new open and laparoscopic techniques are described. Compared with open donor nephrectomy, laparoscopic donor nephrectomy has shown superior results in terms of postoperative pain, cosmetics, convalescence, and return to normal daily activities. No significant differences exist between the two approaches in terms of complication rates, cost-effectiveness and graft function. Nowadays, laparoscopic donor nephrectomy has become the preferred method for procuring kidney grafts of living donors in many centres.

Pulsatile perfusion preservation of warm ischaemia-damaged experimental kidney grafts

Background

Cold storage using histidine–tryptophan–ketoglutarate (HTK) solution is used widely in clinical practice for the preservation of warm ischaemia-damaged kidney grafts. This study assessed the efficacy of pulsatile machine perfusion in combination with Polysol® for the preservation of warm ischaemia-damaged kidney grafts.

Methods

After induction of warm ischaemia by clamping of the left renal pedicle for 30 min, pigs were subjected to left nephrectomy. Thereafter, grafts were preserved for 20 h by cold storage with HTK (CS-HTK) or Polysol® (CS-PS), or machine preservation with Polysol® (MP-PS). Subsequently, contralateral kidneys were removed and preserved kidneys were transplanted. Control pigs underwent unilateral nephrectomy. Renal function was assessed daily for 1 week. Kidney biopsies were analysed for morphology and proliferative response.

Results

Renal function of warm ischaemia-damaged grafts preserved using MP-PS was comparable to that of non-ischaemic controls. MP-PS and CS-PS groups showed improved renal function compared with the CS-HTK group, with more favourable results for MP-PS than for CS-PS. The proliferative response of tubular cells in the CS-HTK group was higher than in all other groups.

Conclusion

This study demonstrated that the function of warm ischaemia-damaged kidney grafts after pulsatile perfusion preservation was comparable to that of non-ischaemic controls.

Multiple bacteria contribute to intraplaque T-cell activation in atherosclerosis

BACKGROUND

Infection with microorganisms is considered a pathogenic factor in atherogenesis. Several studies have shown the presence of a broad spectrum of bacterial species in atherosclerotic plaques, which could trigger local inflammation. Because T cells contribute to atherosclerotic plaque inflammation, we studied the responsiveness of human plaque derived T-cell cultures to bacteria of different species.

MATERIALS AND METHODS

Primary polyclonal T-cell cultures were generated from both carotid endarterectomy tissue and peripheral blood of nine patients, and the peripheral blood of eight matched controls. The in vitro proliferative responses of the T-cell cultures against H. pylori, N. meningitidis, N. lactamica, S. aureus, S. pneumoniae, S. epidermidis and E. coli were analysed. T-cell proliferation was measured by (3)H-thymidine incorporation and expressed as a stimulation index. Selective outgrowth of intraplaque microbial specific T cells was studied by calculating the ratio of plaque T-cell SI and peripheral blood T-cell SI in each patient.

RESULTS

All patients showed T-cell responsiveness to multiple bacteria in their plaque tissue. Stimulation indices were in the range of 0.3-30, and this degree of reactivity with the different species was heterogeneous among patients. Selective outgrowth (plaque/peripheral blood ratio) of T cells against multiple bacteria was observed in six out of nine patients.

CONCLUSIONS

T cells in atherosclerotic plaques have the capacity to selectively respond to antigens of a wide variety of microbial antigens. This supports the view that such mechanisms could contribute to the atherosclerotic inflammatory response.

Catastrophic antiphospholipid syndrome mimicking a malignant pancreatic tumour – a case report

Abstract

The catastrophic antiphospholipid syndrome is characterised by rapid onset thromboses, often resistant to conventional anticoagulant treatment, and resulting in life threatening multiple organ dysfunction. The diagnosis of catastrophic antiphospholipid syndrome may be difficult, predominantly due to its frequently atypical presentation. We report a case of a 35-year-old female who presented with a pancreatic tumour and extensive thromboses. Following a storm of ischemic events due to thrombotic occlusions in spite of therapeutic heparin dose, the suspicion of catastrophic antiphospholipid syndrome emerged. The patient was successfully treated with anticoagulants, immunuglobulins, plasmapheresis and rituximab. The present report shows that the use of the diluted Russell’s viper venom time can be helpful in providing additional information on the lupus anticoagulans antibody status, allowing careful monitoring of lupus anticoagulans conversion and hence response to therapy.

Meta-analysis of the Clinical Effectiveness of Venous Arterialization for Salvage of Critically Ischaemic Limbs

OBJECTIVE

The aim of this study is to assess the clinical effectiveness of venous arterialization in patients with critical limb ischaemia not reconstructable by conventional bypass.

DESIGN

Meta-analysis of observational studies.

MATERIALS

Eligible studies concerning treatment by venous arterialization for chronic critical leg ischaemia were identified from electronic database, cross-reference search and pertinent articles. There was no language restriction.

METHODS

All relevant studies were systematically reviewed and data extracted by two independent reviewers. Study endpoints were foot preservation, secondary graft patency, postoperative clinical improvement and complications.

RESULTS

A total of 56 studies were selected for comprehensive review. No RCTs were identified. Seven patient series, comprising 228 patients, matched the selection criteria. Overall 1-year foot preservation was 71% (95% CI: 64-77%) and 1-year secondary patency was 46% (95% CI: 39-53%). The large majority of patients in whom major amputation was avoided experienced successful wound healing, disappearance of rest pain and absence of serious complications.

CONCLUSION

On the basis of limited evidence, venous arterialization may be considered as a viable alternative before major amputation is undertaken in patients with 'inoperable' chronic critical leg ischaemia.

[The first 100 hand-assisted laparoscopic donor nephrectomies at the Academic Medical Center in Amsterdam]

OBJECTIVE

To evaluate the results of the first 100 hand-assisted donor nephrectomies in our hospital.

DESIGN

Prospective, descriptive.

METHOD

In the period January 2000-July 2004, 100 consecutive donors underwent laparoscopic nephrectomy as part of a living-related kidney transplantation at the Academic Medical Center in Amsterdam, the Netherlands. The operation was performed laparoscopically using a hand port (hand-assisted nephrectomy). The incision made for the hand port was also used for the removal of the kidney.

RESULTS

Mean operating time was 168 min (range: 88-285). Median warm ischaemia time was 3 min (1.0-4.5) and median blood loss was 50 ml (20-1500). None of the operations required conversion to an open procedure and there were no deaths among donors or recipients. Postoperatively, 12 complications occurred in 10 donors. Median hospital stay for the donors was 5 days. In 3 recipients, the transplanted kidney had to be removed within 14 days. 1n 3 other recipients, surgical re-intervention was necessary due to urological complications. One-year graft survival was 94%.

CONCLUSION

Hand-assisted laparoscopic donor nephrectomy was a safe and minimally invasive procedure for renal transplantation in this patient series.

Morphological and functional alterations in glycerol preserved rat aortic allografts

Glycerol preservation is an effective method for long-term preservation of skin allografts and has a potential use in preserving arterial allografts. We evaluated the effect of glycerol concentration and incubation period on vessel-wall integrity of rat aortic allografts. No significant differences were measured in breaking strength (2.3 +/- 0.3 N) and bursting pressure (223 +/- 32 kPa) between standard glycerolized and control segments (1.7 +/- 0.3 N, 226 +/- 17 kPa). Isometric tension measurements showed complete lack of functional contraction and relaxation capacity in allograft segments prepared according to all preservation protocols. Morphologically, thickness of the vessel-wall media diminished after preservation using low (30/50/75%) or high (70/85/98%) concentrations of glycerol, as compared to control segments (i.e. 81 +/- 2.4 microm, 95 +/- 5.6 microm and 125 +/- 3.5 microm, respectively). Confocal microscopy and Fourier analysis demonstrated that vascular collagen and elastin bundle orientation had remained unaltered. Electron microscopy showed defragmentation of luminal endothelial cells. In conclusion, glycerol preservation of rat aorta resulted in an acellular tissue matrix, which maintained biomechanical integrity and extracellular matrix characteristics. The next step in the investigation will be to test the concept of glycerol preservation of arterial allografts in a vascular transplantation model.

Visceral and Renal Tissue Oxygenation During Supraceliac Aortic Crossclamping and Left Heart Bypass with Selective Organ Perfusion

INTRODUCTION

Left-heart bypass (LHB) and selective organ perfusion (SOP) are used during thoracoabdominal aortic surgery to prevent ischemic damage to the kidneys and visceral organs after supraceliac aortic crossclamping. We studied the hypothesis, in a porcine model, that despite LHB and maximal SOP, visceral and renal ischemia still occurred during surgery.

MATERIAL AND METHODS

Eleven pigs (54-70 kg) were coupled to a non-pulsatile LHB with inflow and outflow at the lower thoracic and distal infrarenal aorta, respectively. After supracoeliac and infrarenal aortic crossclamping, SOP was started using perfusion catheters. The proximal and distal mean aortic blood pressures were kept above 70 and 50 mmHg, respectively, while the mean blood pressure within the SOP system was above 60 mmHg. The visceral and renal tissue oxygenation was measured by intermittent blood gas analysis, from the portal and both renal veins. The jejunal mucosal oxygenation was measured by tonometric measurement of the luminal pCO2.

RESULTS

Measured median blood blood flow through the LHB and the SOP system were 800 and 1140 ml/min, respectively. Median blood flow prior to, and during LHB and SOP through the celiac artery, superior mesenteric artery, and left renal artery were 300 and 240, 762 and 295, and 235 and 235 ml/min, respectively. During 3 h of LHB and SOP no significant changes in the renal tissue oxygenation were noted compared with the physiological situation prior to supracoeliac aortic crossclamping and cannulation. However, in the visceral vascular bed median mixed venous oxygen saturation dropped from 79 to 63% (p<0.001), and median oxygen extraction ratio increased from 26 to 41% (p<0.001). Median tonometric measured intraluminal jejunal pCO2 increased from 9.9 to 12.15 kPa (p>0.05). During 3 h of LHB and SOP no hemolysis was detected, as there was no rise in serum LDH.

CONCLUSION

LHB and SOP preserves renal but not visceral tissue oxygenation during supraceliac aortic crossclamping and does not induce hemolysis.

Duplex scan surveillance during the first year after infrainguinal autologous vein bypass grafting surgery: costs and clinical outcomes compared with other surveillance programs

PURPOSE

In this study we assessed the costs and clinical outcomes of duplex scan surveillance during the first year after infrainguinal autologous vein bypass grafting surgery and compared duplex scan surveillance, ankle-brachial index surveillance, and clinical follow-up.

METHODS

In a clinical study, 293 patients (mean age, 70.1 years; 58.7% men) with peripheral arterial disease were observed in a duplex scan surveillance program after infrainguinal autologous vein bypass grafting surgery. Costs were calculated from the health care perspective for surveillance and subsequent interventions from 30 days to 1 year postoperatively. All costs are presented in 1995 US dollars per patient. In a simulation model, we estimated the costs and amputations of duplex scan surveillance, ankle-brachial index surveillance, and clinical follow-up conditional on the indication for surgery. The main outcome measure was the incremental cost per major amputation per patient avoided during the first postoperative year.

RESULTS

Duplex scan surveillance was the least expensive ($2823) and resulted in the fewest major amputations (17 per 1000 patients examined), compared with ankle-brachial index surveillance ($5411 and 77 amputations per 1000 patients) and clinical follow-up ($5072 and 77 amputations per 1000 patients). In patients treated for critical limb ischemia, duplex scan surveillance was the least expensive ($2974) and resulted in the fewest major amputations (19 per 1000 patients). Under all surveillance programs, 13 major amputations per 1000 patients treated for intermittent claudication were performed, and clinical follow-up had the lowest costs ($1577). In a sensitivity analysis that assumed that duplex scan surveillance could have avoided six major amputations per 1000 patients treated for intermittent claudication compared with the other programs, duplex scan surveillance had an incremental cost of $80,708 per major amputation per patient avoided compared with clinical follow-up.

CONCLUSION

Duplex scan surveillance is highly effective for patients treated for critical limb ischemia, leading to a reduction of major amputations and consequently to a reduction in costs compared with other surveillance programs. In patients treated for intermittent claudication, the evidence supporting duplex scan surveillance is less firm, but if duplex scan can avoid six major amputations per 1000 patients examined, the incremental costs are justified.

Factors influencing the development of vein-graft stenosis and their significance for clinical management

OBJECTIVES

To assess the influence of clinical and graft factors on the development of stenotic lesions. In addition the implications of any significant correlation for duplex surveillance schedules or surgical bypass techniques was examined.

PATIENTS AND METHODS

In a prospective three centre study, preoperative and peroperative data on 300 infrainguinal autologous vein grafts was analysed. All grafts were monitored by a strict duplex surveillance program and all received an angiogram in the first postoperative year. A revision was only performed if there was evidence of a stenosis of 70% diameter reduction or greater on the angiogram.

RESULTS

The minimum graft diameter was the only factor correlated significantly with the development of a significant graft stenosis (PSV-ratio > or = 2.5) during follow-up (p = 0.002). Factors that correlated with the development of event-causing graft stenosis, associated with revision or occlusion, were minimal graft diameter (p = 0.001), the use of a venovenous anastomosis (p = 0.005) and length of the graft (p = 0.025). Multivariate regression analysis revealed that the minimal graft diameter was the only independent factor that significantly correlated with an event-causing graft stenosis (p = 0.009). The stenosis-free rates for grafts with a minimal diameter < 3.5 mm, between 3.5-4.5 and > or = 4.5 mm were 40%, 58% and 75%, respectively (p = < 0.05). Composite vein and arm-vein grafts with minimal diameters > or = 3.5 mm were compared with grafts which consisted of a single uninterrupted greater saphenous vein with a minimal diameter of < 3.5 mm. One-year secondary patency rates in these categories were of 94% and 76%, respectively (p = 0.03).

CONCLUSIONS

A minimal graft diameter < 3.5 mm was the only factor that significantly correlated with the development of a graft-stenosis. However, veins with larger diameters may still develop stenotic lesions. Composite vein and arm-vein grafts should be used rather than uninterrupted small caliber saphenous veins.

Economising vein-graft surveillance programs

OBJECTIVES

To investigate the effectiveness of two alternative vein-graft surveillance strategies. In the first strategy surveillance was restricted to patients with a possible higher risk of significant stenosis development, i.e., those with a moderate stenosis identified early after the operation. In the second strategy the effects of reducing the number of duplex tests per patient was examined.

PATIENTS AND METHODS

In a prospective study in three vascular surgical departments 300 patients (300 femoropopliteal or distal grafts) underwent duplex surveillance during the first year after the operation. The duplex-derived PSV-ratio was considered to represent the degree of stenosis. Arteriographic confirmation of suspected stenoses was routinely obtained, and patients without a suspected graft stenosis underwent a consented arteriogram during the first postoperative year. The decision to perform a graft revision was taken on the basis of an arteriographic stenosis of at least 70% diameter reduction. In the first strategy graft categories were defined on the basis of the first postoperative duplex examination: grafts with a PSV-ratio < 1.5, grafts with a PSV-ratio < 1.5-2.0, grafts with a PSV-ratio of 2.0-2.5, grafts with PSV-ratios 2.5-3.0, and grafts with PSV-ratios > 3.0. The primary patency rate at 12 months was compared for these categories. In the second alternative strategy the number of examinations and the percentage of event causing de novo stenoses were analysed per surveillance interval.

RESULTS

The presence of moderate abnormalities at the initial duplex scan did not identify patients with a high risk of an event, as initial PSV-ratios of 1.5-2.0 and 2.0-2.5 (early mild-moderate lesions) had comparable 12-month primary patencies to patients with a PSV-ratio < 1.5 (completely normal grafts): (63%, 73%, and 71%, respectively). The interval incidence of event causing de novo stenoses was 8% of the total number of duplex tests performed at 3 months, and 8% at 6 months after the operation. In patients who had no previous intervention for stenosis and had a normal bypass during the first 6 months postoperatively, a sharp drop in this incidence was seen at 9 and 12 months, with event causing de novo stenoses observed in only 2% and 1% of all duplex tests.

CONCLUSIONS

All patients should be included in a surveillance program, as the presence of a normal vein graft at the first duplex examination does not rule out the subsequent development of graft stenosis. The duration of the surveillance period may be restricted to the first 6 months after operation in patients who have a normal bypass during that time period, as only few stenoses will be missed by this policy.

Vein graft surveillance: is graft revision without angiography justified and what criteria should be used?

PURPOSE

The objective of this study was to assess the accuracy of color-flow duplex surveillance parameters to detect infrainguinal vein graft stenoses and to investigate whether graft revision without angiography is justified.

METHODS

In a prospective study in which three centers participated, the data of graft surveillance in 300 patients were analyzed. For the evaluation of surveillance criteria all patients underwent a digital subtraction angiography if a graft stenosis was suspected. To create a control group, in patients with normal grafts a consented digital subtraction angiography was performed also. From these data the accuracy of seven duplex and three ankle blood pressure-derived variables was assessed. The relation between various surveillance criteria and continued graft patency was determined with life table analysis with the transient state method.

RESULTS

The mean follow-up period was 20 months (range, 1 to 40 months). At univariate and multivariate analysis the peak systolic velocity (PSV) ratio provided the best correlation with angiographic stenoses > or = 70% (PSV ratio cutoff 3.0: sensitivity 80%, specificity 84%). This finding did not differ between the participating centers. With life table methods it was demonstrated that the best combination of efficacy (limitation of the number of unnecessary revisions), safety (minimal number of correctable lesions missed), and reduction of angiograms was obtained by a two-parameter surveillance algorithm. This algorithm included a PSV ratio < 2.5 to delineate patients in whom a conservative approach without angiography or revision was appropriate, a PSV ratio > or = 4.0 to indicate patients in whom vein graft revision without angiography could be scheduled, and a group with PSV ratios between 2.5 and 4.0 in whom angiography was to be performed to determine clinical management on the basis of the stenosis severity. This algorithm had a positive predictive value of 93% and a negative predictive value of 89%. In addition, it resulted in a reduction of the number of angiograms of 49% compared with a policy of angiographies in all patients with a PSV ratio > or = 2.5.

CONCLUSIONS

The best criterion to identify a failing graft is the PSV ratio. With a two-parameter algorithm for vein graft surveillance, the incidence of unnecessary revisions and of missed high-grade lesions was acceptably low, whereas the number of angiograms was reduced by one half.

Impact of a color-flow duplex surveillance program on infrainguinal vein graft patency: a five-year experience

PURPOSE AND METHODS

The contribution of color-flow duplex surveillance to improving vein graft patency was evaluated in two patient groups after 201 infrainguinal bypass procedures were performed during a 5-year period. Incidence of revision procedures and the primary and assisted primary patency rates were compared for 160 bypass grafts monitored during the first 2 years by use of color-flow duplex scanning of the vein graft and adjacent arterial segments (color-flow surveillance group) versus 41 bypass grafts monitored by use of clinical assessment alone (clinical follow-up group). Only grafts that were patent after the first postoperative month are considered.

RESULTS

The two groups were comparable with regard to most of the pertinent clinical factors. Stenotic lesions were identified in 58 bypass grafts, and severity was determined by use of intraarterial digital subtraction angiography. Eighteen bypass grafts with stenoses did not undergo a revision for reasons that were determined by the doctor, the hospital, or the patient. The occlusion rates of revised and nonrevised stenotic grafts were compared for lesions of different severity. None of the grafts for stenoses with 30% to 49% diameter reduction (DR) failed during follow-up. Occlusion occurred in 57% of the nonrevised and 9% of revised grafts (p = 0.047) for stenoses with 50% to 69% DR. Stenoses with 70% or greater DR were associated with graft failure in 100% of nonrevised bypasses and in 10% of revised grafts (p = 0.004). The assisted primary patency rate was higher in grafts that underwent color-flow surveillance compared with grafts with that underwent clinical follow-up (3-year patency rates of 91% and 72%, respectively; p = 0.004). The independent correlation of color-flow surveillance with higher patency rates was demonstrated in a proportional hazard analysis. The relative risk (probability of occlusion) in color-flow surveillance grafts is less than one third of the relative risk in bypass grafts that underwent clinical follow-up.

CONCLUSIONS

We conclude that revision procedures were more optimally used during color-flow surveillance, whereas asymptomatic stenotic graft lesions are missed with clinical follow-up, which results in a higher percentage of graft failures. Overall graft patency rates can be improved with use of color-flow duplex surveillance and repair of significant stenotic lesions.

Surveillance of lower extremity vein grafts

Development of stenosis in lower extremity vein grafts or its anastomotic segments is responsible for most graft failures. While these lesions can be treated by minor procedures, timely identification may improve long-term graft patency. In this review, diagnostic methods that are currently applied for vein graft surveillance, criteria for stenosis and recommendations for intervention are discussed.