[Hybrid operating rooms versus conventional operating rooms : Economic comparisons in vascular surgery using the example of endovascular aneurysm repair]. / Hybridoperationssaal vs. konventioneller Operationssaal : Betriebswirtschaftliche Gegenüberstellung in der Gefäßchirurgie am Beispiel der endovaskulären Aneurysmachirurgie.

BACKGROUND: With changing treatment modalities in vascular surgery towards incorporating more endovascular solutions, increased numbers of hybrid operating theatres are being introduced to meet the sterility and imaging quality requirements. These cost-intensive acquisitions however have never been evaluated from an economic perspective. In this study we evaluated cost-relevant parameters before and after the introduction of a hybrid operating room using the example of endovascular aneurysm repair (EVAR) performed in patients with abdominal aortic aneurysms (AAA). METHODS: Retrospective analysis of prospectively collected data. The 4­year period before the introduction of a hybrid operating room were compared with the 4­year period following introduction. Between 2007 and 2010, 97 EVAR procedures were performed before the implementation of a hybrid operating room and 50 EVAR procedures were performed with a hybrid operating room (2012-2015). We evaluated process cost-relevant parameters (operating time) and diagnosis-related group (DRG) parameters (case load, case mix, case mix index). RESULTS: The operating time was significantly reduced on average by 23.5 min (120 min [102-140] vs. 96.5 min [90-120]; p < 0.0001) with a hybrid operating room. This led to a reduction in costs of 276.17 EUR for an EVAR procedure. The case load of EVAR increased from 308 cases from 2007-2010 to 380 cases from 2012-2015 . The associated case mix also increased from 1580 to 1986 points. The total number of case mix points of all managed operative interventions in the operating theatre before and after conversion to a hybrid operating room grew significantly by 17.33% from 8420 to 9880 (p < 0.03) in the compared time periods. CONCLUSION: With detailed, demand-oriented planning, a hybrid operating room can have a favourable economic effect due to a reduction of operating time and the overall lowering of process costs. Thus a refinancing in the long-term is feasible. In addition, this can lead to an increase in the total number and complexity of endovascular procedures.

Eversion carotid endarterectomy is associated with decreased baroreceptor sensitivity compared to the conventional technique.

OBJECTIVE: Impairment of baroreceptor sensitivity (BRS) has been shown to be associated with blood pressure instability after carotid endarterectomy (CEA). The aim of this study was to determine whether there is a difference in postoperative BRS changes following eversion CEA (E-CEA) and conventional CEA (C-CEA). METHODS: Sixty-four patients undergoing E-CEA (n = 37) and C-CEA (n = 27) were prospectively studied. Non-invasive measurements of mean arterial pressure (MAP), cardiac output (CO) and total peripheral resistance (TPR) were perioperatively obtained over three 10-min periods. Baroreflex gain was calculated as the sequential cross-correlation between heart rate and beat-to-beat systolic blood pressure. RESULTS: Compared with changes observed after C-CEA, E-CEA was associated with an increase in systolic pressure (SP) (P = 0.01), diastolic pressure (DP) (P = 0.008), MAP (P = 0.002) and heart rate (HR) (P = 0.03) on postoperative day 1 (POD-1). BRS decreased after E-CEA from 6.33 to 4.71 ms mmHg(-1) on POD-1 (P = 0.001) and to 5.26 ms mmHg(-1) on POD-3 (P = 0.0004). By contrast, BRS increased after C-CEA from 4.59 to 6.13 ms mmHg(-1) on POD-1 (P = 0.002) and to 6.27 ms mmHg(-1) on POD-3 (P < 0.0001). CONCLUSION: E-CEA and C-CEA have different effects on BRS. This is associated with an altered haemodynamic behaviour after E-CEA and C-CEA, respectively. These findings are likely the result of carotid sinus nerve interruption during E-CEA and preservation with C-CEA.

Critical limb ischaemia: initial treatment and predictors of amputation-free survival.

OBJECTIVES: To evaluate initial treatment and risk factors for amputation-free survival in patients with critical limb ischaemia (CLI). DESIGN: Prospective clinical cohort study at a single vascular surgical centre in Germany. METHODS: Data on 104 consecutive patients (115 ischaemic limbs) presenting with their first episode of CLI were collected prospectively over a 3-year period. Initial treatment was classified as conservative therapy, intervention, surgery, or major amputation. Patient co-morbidities were assessed by uni- and multivariate analysis to determine risk factors for limb salvage, survival and amputation-free survival. RESULTS: Indications for treatment were rest pain in 27 (23.5%) and tissue loss in 88 (76.5%) limbs. Revascularisation was attempted in 65% of all limbs: 45% by intervention and 55% by surgery. In 9% primary amputation was necessary and 22% received conservative therapy. Median follow-up was 28 months (1-42). The 3-year limb salvage, patient survival, and amputation-free survival rates were 73%, 41%, and 31%, respectively. Diabetes, cardiac disease and renal insufficiency were associated with poor survival. Combined cardiac and renal disease adversely affected amputation-free survival (HR, 3.68; 95% CI, 1.51-8.94; P < 0.001). CONCLUSIONS: At least two third of all patients presenting with CLI can be offered some type of direct revascularisation. In patients with major cardiac disease and renal insufficiency, a poor outcome in terms of amputation-free survival is to be anticipated.

Prospective 2-years follow-up quality of life study after infrageniculate bypass surgery for limb salvage: lasting improvements only in non-diabetic patients.

OBJECTIVES: To assess health-related quality of life (HRQoL) up to 24 months after successful infrageniculate bypass surgery for limb-threatening ischaemia. METHODS: 89 patients with infrageniculate bypass surgery for limb-salvage were studied. HRQoL was assessed using the Short Form (SF)-36v1 questionnaire before, 6, 12, and 24 months after revascularisation. RESULTS: 47 patients (53%) with intact limb and functioning graft were assessed after 24 months, 27 patients (30%) died, further 7 required secondary amputation, 3 suffered irremediable graft occlusion, and 4 were lost to follow-up. The 24-months HRQoL-values were significantly improved in 4 domains: physical functioning (p<0.01), bodily pain (p<0.01), mental health (p=0.04), and social functioning (p=0.01). Except for baseline-values, HRQoL remained inferior in diabetics compared to non-diabetics throughout follow-up. Maximum improvement of HRQoL was delayed in diabetics (12 months vs. 6 months) and less pronounced. After 24 months non-diabetic patients maintained improvement in 5 domains and diabetic patients only in bodily pain. CONCLUSIONS: Improvement in HRQoL is sustained for more than 12 months after successful infrageniculate bypass surgery. Therefore, an aggressive approach towards revascularisation seems to be justified from the patient's perspective. However, this benefit in quality of life is less in diabetic patients, despite similar limb-salvage rates.

Improvement of quality of life six months after infrageniculate bypass surgery: diabetic patients benefit less than non-diabetic patients.

OBJECTIVES: The aim of the study was to assess the change in health related quality of life (HRQoL) after infrageniculate bypass grafting in patients with critical limb ischaemia (CLI). DESIGN: Observational, prospective clinical study. MATERIALS AND METHODS: In total, 86 patients (72% male; age 71 (IQR, 64-78) years) undergoing infrageniculate bypass grafting for limb salvage were assessed by the short form (SF)-36 questionnaire before and 6 months after surgery. In subgroup analysis, the influence of diabetes mellitus, age, gender, and stage of peripheral arterial occlusive disease on HRQoL-outcome were assessed. RESULTS: Following revascularization HRQoL significantly improved in all eight dimensions of the SF-36. While baseline HRQoL-values of diabetic and non-diabetic patients did not differ significantly, postoperative improvement was significantly less in the diabetes group. CONCLUSIONS: An aggressive approach towards infrageniculate bypass surgery for limb salvage is justified by quality of life improvement. However, this improvement tends to be less in patients with diabetes mellitus.

Risk factors for survival in patients with end-stage renal disease undergoing infrainguinal bypass surgery.

BACKGROUND: A poor longevity and high perioperative morbidity make lower extremity revascularization questionable in patients with end-stage renal disease (ESRD). Therefore, careful selection of patients for surgery is essential. Aim of this study was to assess negative predictors of survival in patients with ESRD undergoing infrainguinal bypass grafting for critical limb ischemia (CLI). PATIENTS AND METHODS: We reviewed the records of 49 consecutive patients with ESRD who underwent infrainguinal bypass grafting for limb salvage. Rates were computed with life-table analysis and compared by log-rank test. Effects of demographic and disease variables on the survival rate were evaluated by Cox proportional hazard regression model. RESULTS: Indications for surgery were rest pain in two (4.1%) and tissue loss in 4 7 patients (95.9%). Median follow up was 7.8 months (IQR, 2.43 to 16.23). Perioperative (30-day) morbidity and mortality for all patients were 6.1% and 12.2%, respectively. Primary and secondary patency at two years both were 81.4%. Cumulative survival rate at two years and four years were 24.9% and 9.3%, respectively Limb salvage rate and amputation-free survival rate at two and four years were 80.4%, 53.6%, 21.8% and 14.6%, respectively. Myocardial infarction and congestive heartfailure in the patients medical history both had an adverse effect on survival rate with a hazard ratio of 5.52 (95% CI, 1.94 to 15.69) and 3.12 (95% CI, 0.99 to 9.81), respectively. CONCLUSIONS: In the presence of myocardial infarction or congestive heart failure in the medical history survival rate is especially poor for patients with ESRD undergoing infrainguinal revascularization. Therefore, bypass surgery for CLI is hardly indicated in this group of patients.

Duplex scanning criteria for selection of patients for internal carotid artery endarterectomy.

BACKGROUND: The value of carotid endarterectomy for stroke prevention depends on reliable identification of patients at higher risk for stroke from their internal carotid artery (ICA) occlusive disease than from surgery. This selection of patients is based on the degree of ICA stenosis. Therefore, preoperative diagnostic measures should strive for a prevalence independent probability for disease of 100%. Aim of this prospective study was to obtain clinically applicable duplex scanning criteria for ICA stenosis > or = 70% with a probability for disease of 100%. PATIENTS AND METHODS: In 124 ICA in 62 patients (79% male) angiography and duplex scanning were performed. Degree of stenosis was classified in 4 categories: I < 50%; II 50%-69%; III 70%-99%; IV 100%. Cohen's kappa statistic was used to estimate agreement between both methods within categories. To improve accuracy post-test likelihood for disease was calculated for each point on the receiver operating characteristics (ROC)-curve for peak systolic (PSV) and end-diastolic velocity (EDV), and cut-off points for velocity criteria were set at a positive likelihood of 100%. RESULTS: Diagnostic agreement was good with kappa = 0.77 (95% CI, 0.64-0.90; p < 0.001). For EDV a criterion of > or = 150 cm/sec was associated with a post-test likelihood for disease of 100%. For PSV no appropriate criterion could be detected. CONCLUSIONS: A probability of 100% for ICA stenosis > or = 70% can be achieved by mere preoperative duplex scanning. Vascular laboratory specific validation of duplex scanning criteria should consider prevalence independent post-test likelihood for disease to ensure the value of CEA for stroke prevention.

Transperitoneal versus retroperitoneal approach for treatment of infrarenal aortic aneurysms: is one superior?

BACKGROUND: As endovascular treatment of asymptomatic infrarenal abdominal aortic aneurysm (AAA) increasingly competes with surgical repair, it is necessary to optimize the surgical technique. The aim of this study was therefore to evaluate the superiority of either retroperitoneal (RP) or transperitoneal (TP) approach. PATIENTS AND METHODS: Intra- and peri-operative data from 80 patients with infrarenal AAA and tube graft repair were analysed retrospectively. The RP-approach was used in 37 patients and in 43 the transperitoneal. RESULTS: There was no relevant difference in demographic data and anaesthetic regime; exceptions were differences between the two groups in terms of age (median RP 72.31 vs. TP 68.58 years, p = 0.0174), hypertension (RP 26/37 vs. TP 40/43, p = 0.0019), smoking (RP 25/37 vs. TP 38/43, p = 0.0462), pulmonary diseases (RP 15/37 vs. TP 7/43, p = 0.0232), and previous abdominal surgery (RP 3/37 vs. TP 12/43, p = 0.042). No patient died during the first 30 post-operative days. The RP-group had a longer cross-clamping time (median RP 50 vs. TP 45 min, p = 0.0115) but no difference was found in operating time. Intra-operative blood loss was higher in the RP-group (median RP 800 vs. TP 500 ml, p = 0.033) with an increased need for blood substitutes (median RP 1 vs. TP 0 packed red cells, p = 0.0068). Time spent in ICU was shorter (median RP 24 vs. TP 46 hours, p = 0.0104), but duration of hospitalisation was longer for the RP-group (median RP 13 vs. TP 10.5 days, p = 0.0156). No differences were found in the need for analgesics, the frequency of procedure related complications, and post-operative recovery. CONCLUSIONS: Surgical repair of AAA in selected patients by tube graft placement is a safe procedure independent of the approach. In particular, our findings do not support previously reported superiority of the RP-approach.

Early carotid endarterectomy in patients with a nondisabling ischemic stroke: results of a retrospective analysis.

BACKGROUND: There are several recent recommendations not to delay carotid endarterectomy (CEA) for at least 4 weeks in patients experiencing a nondisabling ischemic stroke. Therefore, we re-examined if these patients could be safely operated on earlier: The aim of our study was to review the perioperative stroke and death rates of CEA performed within 30 days of stroke onset. PATIENTS AND METHODS: During a 4 year period until December 2001, in 66 neurologically stable patients suffering a nondisabling stroke ipsilateral to a carotid artery stenosis > 50% CEA was performed after a median interval of 10 (1-28) days. The modified Rankin scale (mRS) was applied to characterize the severity of impairment of daily living activities pre- and postoperatively: Any postoperative deterioration > 24 hours on the mRS was considered as a new stroke. RESULTS: Operative mortality was 0%, and postoperative neurologic worsening > 24 hours occurred in 8/66 patients (12.1%). In 5/8 patients neurologic deterioration resolved within 5 days after surgery, only one stroke was permanent (1.5%). There was no correlation between timing of surgery or the presence of acute ipsilateral cranial CT defects with the occurrence of postoperative stroke. Stroke severity grading on admission according to the mRS, however, emerged to be a significant determinant of postoperative outcome: While 6/23 patients (26%) with an initial deficit > or = 3 on the mRS developed neurologic worsening, this was the case in only 2/43 patients (4.6%) with a deficit < or = 2 (Odds Ratio 7.2; 95% CI 1.32-39.49; two-sided p = 0.01). CONCLUSION: Our results suggest that selected patients with a minor stroke (mRS < or = 2 on admission) can safely undergo early CEA.

[Infrainguinal bypass grafting in patients with end-stage renal disease and critical limb ischaemia: is it worthwhile?]. / Infrainguinale Bypassoperationen bei Patienten mit terminaler Niereninsuffizienz und kritischer Beinischämie: Lohnt sich der Aufwand?

Patients with end-stage renal disease (ESRD) constitute an increasing proportion of patients undergoing infrainguinal bypass surgery for critical limb ischaemia (CLI). The aim of this retrospective study was to determine graft patency, healing of pedal lesions, limb salvage and survival following infrainguinal arterial reconstruction in this high-risk subset of patients. 34 patients with ESRD undergoing 37 bypass procedures for CLI (rest pain 2; tissue loss 35) were identified from the vascular registry. These included 13 femoropopliteal and 24 femorotibial bypasses with autogenous (67.6%) or prosthetic (32.4%) materials. The median age in this series was 62 years and 79% were diabetics. Using life-table analysis, the cumulative primary patency rate was 88% at 1 month and 81% at 2 years. The resulting limb salvage rate amounted to 94 and 86% at 1 month and 2 years, respectively. Healing of the pedal lesions was accomplished in only 50% of patients at 6 months. Toe lesions could be treated more successfully than forefoot and deep heel defects (p = 0.04). With a perioperative mortality of 3/37 cumulative survival rate declined to 21% at 2 years. Late mortality correlated significantly with a history of previous myocardial infarction or congestive heart failure (p = 0.001). Infrainguinal revascularisation can be performed in dialysis-dependent patients with acceptable patency and limb salvage rates. However, bypass grafting should be mainly reserved to patients without severe cardiac disease and to those without extensive tissue loss.

Graft patency and clinical outcome of femorodistal arterial reconstruction in diabetic and non-diabetic patients: results of a multicentre comparative analysis.

OBJECTIVE: in diabetic patients with critical limb ischaemia (CLI) an inferior success rate following infrainguinal bypass surgery is quite often suggested. The aim of this retrospective analysis was, therefore, to evaluate the graft patency and, particularly, the clinical outcome at 1 year in diabetic compared with non-diabetic patients. MATERIAL AND METHODS: two hundred and eleven patients (diabetics 94; non-diabetics 117) with femorodistal reconstruction for CLI were studied. Groups were comparable with regard to the Fontaine classification, the distribution of vascular risk factors, graft material, distal anastomosis site, and the angiographic runoff grading. RESULTS: diabetes did not adversely affect graft function. For diabetics and non-diabetics primary cumulative patency rate at 1 year was found to be 66 and 56%, respectively (p=0.10) and a virtually identical limb salvage rate of 85 and 83% was achieved (p=0.76). With regard to healing of ischaemic foot ulcers a trend against diabetics was noted with a healing rate of 81% compared to 96% in non-diabetics at 1 year (p=0.067); gangrenous foot lesions could be equally remedied in 94% and in 87% among patients with and without diabetes (p=0.44). The survival rate of diabetics, however, was significantly lower with 78% at 1 year compared with 95% in non-diabetic patients (p=0.0004). CONCLUSIONS: our preliminary results support the view that infrainguinal bypass grafting can be safely done even in diabetics. Despite increased mortality in this group, liberal indication for reconstructive vascular surgery seems to be justified by favourable patency rates and clinical outcome in selected patients.

[MR-angiography and duplex-ultrasonography: predictive reliability for angiographically determined internal carotid artery stenosis >/= 70-99%]. / MR-Angiographie und Duplexsonographie der Karotiden - Wie zuverlässig kann eine angiographische Diameterreduktion der A. carotis interna >/= 70-99 % erkannt werden?

PURPOSE: A prospective study was undertaken to evaluate whether digital subtraction angiography (DSA) which is still associated with a substantial morbidity can be replaced by less invasive diagnostic modalities such as duplex scanning (DS) and magnetic resonance angiography (MR-A) for the detection of angiographically defined internal carotid artery (ICA) stenosis >/= 70 %. PATIENTS AND METHODS: A total of 47 patients with suspected severe ICA stenosis underwent examination of their carotid arteries using duplex studies, MR-A and DSA. According to the study protocol, the arteriographic diameter reduction (DR) >/= 70 % which had to be predicted by DS and MR-A was determined following the NASCET criteria. RESULTS: Stroke rate following DSA amounted to 2.1 %. In 94 carotid arteries studied by DSA 34 times a DR >/= 70 % was found. Using ROC curve for determining optimal discriminant value, duplex-derived peak systolic velocity (PSV) >/= 250 cm/s provided a sensitivity of 94.1 %, a specificity of 80 %, a positive predictive value (PPV) of 72.7 % and a negative predictive value (NPV) of 96 % to characterise an ICA stenosis >/= 70 %. Due to an inadequate PPV, PSV failed to suffice as the sole preoperative diagnostic modality even if different PSV velocity cut points were applied. On the other hand, end diastolic velocity (EDV) >/= 150 cm/s provided a PPV of 100 % thereby identifying 16/34 ICA stenoses >/= 70 % in our study. MR-A showed a sensitivity of 91.2 %, a specificity of 88.3 %, a PPV of 81.6 %, and a NPV of 94.6 % to predict an ICA stenosis >/= 70 %. CONCLUSION: In our series, both duplex-derived PSV as well as MR-A provided high sensitivity to detect surgically relevant ICA stenosis. However, to select patients for surgery inclusion of EDV proved to be important due to a high PPV and may spare conventional angiography half of patients with stenosis exceeding 70 %.

The role of intraoperative digital subtraction angiography for quality control of standard carotid endarterectomy using patch angioplasty.

The absence of technical defects is considered to be of great importance during carotid endarterectomy (CEA). In this context, both safe surgical technique and intraoperative quality control may be a fundamental part of the operative procedure. We have therefore undertaken a prospective study to evaluate the possible benefits of completion angiography in standard CEA using patch angioplasty. The objectives were three-fold: (1) to identify the incidence of defects requiring prompt revision; (2) to assess the perioperative stroke rate as well as the number of residual stenosis after 6 weeks in angiographically controlled patients and (3) to compare these results with a control group. From 1 January to 30 September 1999 111 patients with 115 consecutive CEAs which had completion angiography (Group A) were prospectively entered into this study. The results in group A were compared with a series of again 111 patients (Group B) which had 116 CEAs without intraoperative quality control between January and September in the year before. Surgical technique was identical in both groups. In general, risk factors were distributed evenly among both group with the exception that in group A were significantly more high-grade ipsilateral ICA stenoses while group B had more patients with diabetes and ipsilateral CT-defects. In group A, angiographic irregularities prompted us to immediate re-exploration in five patients (dilatation of severe ICA spasm 1; re-exploration of distal ICA occlusion 1; reopening of occluded ECA 3). With a 30 day mortality of 0% each perioperative stroke rate was comparable with 3/115 in group A and 3/116 in group B (P=1.0). 2/3 patients with neurological deficits in group A had early postoperative carotid thrombosis--in spite of a normal completion study. Duplex examination after 6 weeks revealed one asymptomatic ICA occlusion in each group. The incidence of residual stenosis (> or =50%) was not significantly different being 3.7% in group A and 3.2% in group B (P=0.85). When applying a safe and simple operative technique for CEA, the incidence of abnormalities warranting immediate correction appears to be a rare event and, therefore, the necessity for obligatory quality control may be questionable. On the other hand, completion DSA allows a simple documentation of the adequacy of the surgical procedure.

Tibioperoneal arterial lesions and critical foot ischaemia: successful management by the use of short vein grafts and percutaneous transluminal angioplasty.

BACKGROUND: In a substantial number of mainly diabetic patients isolated crural arterial lesions are found to be the underlying cause for severe ischaemic foot lesions. Without revascularisation, patients with this specific occlusion pattern will inevitably face major amputation. To attain limb salvage in this setting, since the early eighties short vein grafts were used to bypass the occluded infrapopliteal arteries. More recently, percutaneous transluminal angioplasty (PTA) was also attempted to avoid limb loss in selected patients. PATIENTS AND METHODS: Since May 1986 in 125 patients 130 autologous bypass grafts from the BK-popliteal artery or the proximal tibioperoneal arteries to malleolar vessels were performed in the presence of extended crural arterial occlusions and critical foot ischaemia (rest pain 3, tissue loss 127). In another series in 89 limbs (rest pain 5, tissue loss 84) of 84 patients PTA was done to treat 168 focal stenoses of > 50% diameter reduction and 11 short occlusions in a total of 135 crural arteries. RESULTS: Using life-table analysis, primary and secondary cumulative patency rates for short vein grafts with distal graft origin were 90% and 98% at 30 days, 76% and 83% at one year and 46% and 49% at seven years, respectively. The corresponding limb salvage rates amounted to 95%, 80% and 63%. Initial complete or partial technical success after PTA of crural arteries could be obtained in 93%: The limb salvage rates achieved were 95% at 30 days, 82% at one year and 63% at six years. CONCLUSION: Our results suggest that--depending on the extent of lesions--both short vein grafts as well as PTA are successful complementary treatment modalities to avoid limb loss in predominantly diabetic patients with infrapopliteal artery disease and critical ischaemia.

The importance of graft blood flow and peripheral outflow resistance for early patency in infrainguinal arterial reconstructions.

BACKGROUND: At present, the importance of functional parameters as determinants for graft patency is under debate. Therefore, in our institution a prospective study was undertaken to evaluate the influence of graft blood flow as well as the currently applied methods for outflow resistance measurement on early (< or = 30 days) graft outcome. PATIENT AND METHODS: 101 arterial revascularisations with infrageniculate graft insertion were entered into this study. After having verified the morphological integrity of the reconstruction, during temporary inflow occlusion total outflow resistance (TOR) was determined as a pressure/flow relationship by perfusion of the graft with saline (flow rates 25, 50, 100, 150 ml/min before and after papaverine) while simultaneously recording pressure generated at the distal anastomosis. In addition, after restoration of blood flow, flow index (FI) was calculated in an analogous way from the TBF through the graft and the respective mean distal anastomotic pressure. Graft patency at 30 days was determined by Duplex ultrasound. RESULTS: Functional parameters were found to be unable to differentiate between patent and failed reconstructions during the 30 day period: The mean TORaveraged values amounted to 722.5 (SD = 310) in patent and 735.9 (SD = 228.1) mPRU in occluded bypasses (T-value = 0.1681; n.s.). The corresponding figures were 176.8 (SD = 94.2) and 196.4 (SD = 93.6) ml/min for TBF (T-value = 0.7342; n.s.) and were 0.53 (SD = 0.34) and 0.45 (SD = 0.25) PRU for FI (T-value = 0.8905; n.s.). Using multiple logistic regression analysis functional parameters showed no influence on graft patency while graft length and the necessity for intraoperative graft modification emerged to be significant determinants of early graft outcome (R2 adjusted = 0.46; p = 0.006). CONCLUSION: The results of our study suggest that neither blood flow nor the presently used methods to assess outflow resistance are relevant prognostic factors for early (< or = 30 days) graft performance.