Pilot Assessment of the Repeatability of Indocyanine Green Fluorescence Imaging and Correlation with Traditional Foot Perfusion Assessments.

BACKGROUND: Ankle brachial index (ABI), toe pressures (TP), and transcutaneous oxygen pressure (TcPO2) are traditionally used in the assessment of critical limb ischemia (CLI). Indocyanine green (ICG) fluorescence imaging can be used to evaluate local circulation in the foot and to evaluate the severity of ischemia. This prospective study analyzed the suitability of a fluorescence imaging system (photodynamic eye [PDE]) in CLI. MATERIAL AND METHODS: Forty-one patients with CLI were included. Of the patients, 66% had diabetes and there was an ischemic tissue lesion in 70% of the limbs. ABI, toe pressures, TcPO2 and ICG-fluorescence imaging (ICG-FI) were measured in each leg. To study the repeatability of the ICG-FI, each patient underwent the study twice. After the procedure, foot circulation was measured using a time-intensity curve, where T1/2 (the time needed to achieve half of the maximum fluorescence intensity) and PDE10 (increase of the intensity during the first 10 s) were determined. A time-intensity curve was plotted using the same areas as for the TcPO2 probes (n=123). RESULTS: The mean ABI was 0.43, TP 21 mmHg, TcPO2 23 mmHg, T1/2 38 s, and PDE10 19 AU. Time-intensity curves were repeatable. In a Bland-Altman scatter plot, the 95% limits of agreement of PDE10 was 9.9 AU and the corresponding value of T1/2 was 14 s. Correlation between ABI and TP was significant (R=.73, p<.001), and it was weaker in diabetic patients (R=.47, p=.048) compared with non-diabetic patients (R=.89, p=.002). Correlations between ABI and TcPO2 and TP and TcPO2 were weak (R=.37, p=.05 and R=.43, p=.037, respectively). Correlation between TcPO2 and PDE10 was strong in diabetic patients (R=.70, p=.003). CONCLUSIONS: According to this pilot study, ICG-FI with PDE can be used in the assessment of blood supply in the ischemic foot.

Rupture of Abdominal Aortic Aneurysms in Patients Under Screening Age and Elective Repair Threshold.

OBJECTIVES: The objective of this study was to identify the proportion of abdominal aortic aneurysm ruptures that occur before the screening age or threshold diameter for operative repair is reached. METHODS: The study was a retrospective analysis of RAAA patients including all RAAA patients admitted to Helsinki (HUH) and Tampere University Hospitals (TaUH) during 2002-2013. The data for age, gender, and comorbidities were collected from vascular registry and patient records. Computed tomography images taken at the time of admission were used for the measurement of maximum anteroposterior (AP) aneurysm diameter at the time of rupture. Age and diameter data were compared with risk factors. RESULTS: A total of 585 patients diagnosed with RAAA were admitted to the two hospitals during the 12 year period. The mean age at the time of rupture was 73.6 years (SD 9.5, range 42-96 years). 18.3% of patients were under 65: 21.4% of men and 3.0% of women. Men were on average 8 years younger than women. The odds ratio (OR) for rupture before 65 years of age for smokers was 2.1 compared with non-smokers, and 28.4% of smokers were under 65 at the time of rupture. Of all RAAA patients, 327 had a computed tomography scan confirming rupture. The mean AP diameter of the aneurysm was 75.6 mm (SD 15.8, range 32-155 mm). The mean size was significantly lower in women than in men (70.5 vs. 76.8, p = .005). CONCLUSIONS: The data from this study show that a fifth of men would not make it to the screening age of 65 before AAA rupture, the proportion being even larger in active smokers. The data from this study also supports the previous finding that aneurysm size at the time of rupture is significantly smaller in women.

Hybrid procedures as a novel technique in the treatment of critical limb ischemia.

In hybrid reconstructions, patients are treated using both endovascular and open revascularization techniques simultaneously. In recent years, these multilevel reconstructions have been increasingly used especially by vascular surgeons as they have adopted new knowledge and endovascular skills and the endovascular techniques have evolved. The first reports of combined endovascular and open surgical procedures are from the 1970s. Since then, most reports have dealt with femoral endarterectomy or femoro-femoral bypass combined with inflow iliac percutaneous transluminal angioplasty (PTA) and stenting. Primary success rates have been high: 93%-100%. In our institution 213 hybrid procedures were performed during 2003-2011 with 98.6% technical success rate. The annual number of hybrid procedures ranged from 4 in 2004 to 73 in 2011. Inflow endovascular procedure was performed in 60% and outflow in 40 % of the cases. The proportion of the endovascular component performed by vascular surgeons increased from 0% in 2004 to 86.3% in 2011. In the current report we review the results published in the literature, report our own experience and present some technical notes and cases.

High leg salvage rate after infrainguinal bypass surgery for ischemic tissue loss (Fontaine IV) is compromised by the short life expectancy.

BACKGROUND AND AIMS: Most studies analysing the prognosis of infrainguinal bypass surgery (IBS) in patients with critical leg ischemia (CLI) have combined the outcome of patients with rest pain and tissue loss. The aim of the present study was to evaluate amputation-free survival (AFS) after IBS in patients with the most advanced form of peripheral arterial disease, CLI with tissue loss (Fontaine IV), and to analyse the risk factors for an adverse outcome. PATIENTS AND METHODS: 636 patients with CLI and tissue loss who underwent unilateral IBS between January 2000 and December 2006 at our institution were included in this retrospective study. RESULTS: At one year, the leg salvage, survival and amputation-free survival rates were 83%, 71% and 55%, respectively, and at five years 76%, 38% and 30%, respectively. In univariate analysis, diabetes was associated with decreased AFS. In multivariate analysis, age, coronary artery disease, chronic pulmonary disease, gangrene and renal insufficiency were independent risk factors for decreased AFS. CONCLUSION: Infrainguinal bypass grafting results in a high rate of leg salvage. Amputation-free survival was low during the follow-up due to the high mortality of patients with CLI and tissue loss. Several co-morbidities of the CLI patients were associated with decreased amputation-free survival.

Healing of ischaemic tissue lesions after infrainguinal bypass surgery for critical leg ischaemia.

OBJECTIVE: To evaluate healing time of ischaemic tissue lesions, limb salvage and survival in patients suffering from critical limb ischaemia (CLI) with tissue loss. DESIGN: Prospective single centre cohort study. MATERIAL AND METHODS: Consecutive patients with CLI and tissue loss (Fontaine IV) (148 patients, 150 limbs) were followed prospectively for 1 year after infrainguinal bypass. Healing time of tissue lesions, graft patency, limb salvage, survival rates and the overall need for any type of surgical and endovascular procedure were analysed. Patient comorbidities were assessed by uni- and multivariate analysis to determine risk factors for adverse outcome. RESULTS: Complete tissue healing, including healing of ischaemic tissue lesions and surgical wounds, at 6 and 12 months after the infrainguinal bypass were respectively 40% and 75%. The median time to complete tissue healing was 190 days. Diabetes was the only significant risk factor which delayed tissue healing. Overall patency, limb salvage, survival and amputation-free survival rates were respectively at 12 months 80%, 81%, 73% and 63%. The clinically important endpoint amputation-free survival with completely healed wounds was attained in 50% of patients at 1 year. CONCLUSION: Complete healing of ischemic tissue lesions is slow even after a successful infrainguinal bypass.

Estimated glomerular filtration rate (eGFR) as a predictor of outcome after infrainguinal bypass in patients with critical limb ischemia.

OBJECTIVES: Renal insufficiency is a risk factor for poor outcome after infrainguinal bypass in patients with critical limb ischemia (CLI). Estimated glomerular filtration rate (eGFR) takes age, gender and body size into account and therefore represents actual renal function more accurately than serum creatinine level alone. The aim of this study was to determine the impact of different stages of renal insufficiency on outcome and to assess the prognostic significance of eGFR in patients with CLI. MATERIAL AND METHODS: 603 patients with CLI who underwent infrainguinal bypass between January 2002 and December 2005 at our institution were included in this retrospective study. We estimated GFR using the Modification of Diet in Renal Disease (MDRD) Study equation. Survival, leg salvage and amputation-free survival were calculated using Kaplan-Meier method. Cox regression analysis was performed to calculate hazard ratios for different outcome variables. RESULTS: Adjusted hazard ratio (HR) of mortality, limb loss and limb loss and/or death for eGFR < 30 ml/min/1.73 m(2) versus serum creatinine > 200 micromol/l was 4.0 (95% CI 2.22-7.39) vs 3.5 (95% CI 1.82-6.84), 6.5 (95% CI 2.71-15.59) vs 6.2 (95% CI 2.47-15.56) and 4.0 (95% CI 2.40-6.63) vs 3.6 (95% CI 2.03-6.25), respectively. CONCLUSION: Estimated GFR is better predictor of survival, leg salvage and amputation-free survival than serum creatinine alone. eGFR < 30 ml/min/1.73 m(2) is independent risk factor for all three outcome endpoints.

Are adverse events after carotid endarterectomy reported comparable in different registries?

OBJECTIVES: To assess the extent of discrepancies between different vascular registries, at various levels of validation, and to investigate whether such differences might alter the morbidity and mortality rates obtained from the gold standard dataset for carotid endarterectomy (CEA). METHODS: All CEA operations in Helsinki University Central Hospital from 2000-2005 were retrieved from the local vascular registry (HUSVASC) and the Hospital Discharge Registry (HILMO). Both registries were validated at different levels to form the final dataset. Total and indication-specific perioperative morbidity and mortality rates were estimated from each level of validation and compared with those from the final dataset and with pooled rates from systematic reviews. RESULTS: Initial search provided 675 and 681 CEAs from HUSVASC and HILMO, respectively, decreasing to 636 (94%) and 614 (90%) when using the specific operative codes for thrombendarterectomy and patch angioplasty. Manual verification of initial HUSVASC results proved that 655 (97%) operations were true CEAs. 18 further proven CEAs, registered only in HILMO, were added to form the final CEA dataset (n=673). The peri-operative morbidity and combined morbidity and mortality rates were 2.23% and 2.67%, respectively. Comparable rates were obtained from both registries, irrespective the level of verification. CONCLUSION: Registry data do not appear to be biased by random loss of some operations and thus they are reliable for decision-making. However, further research is still needed to estimate the permissible volume of omissions in a registry for the data-base to remain trustworthy.

Interplay between coagulation and inflammation in open and endovascular abdominal aortic aneurysm repair--impact of intra-aneurysmal thrombus.

AIMS: Our aim was to compare hemostatic and inflammatory mechanisms in abdominal aortic aneurysm (AAA) patients after open surgery (OPEN) and endovascular AAA repair (ENDO). SUBJECTS AND METHODS: From the 32 consecutive AAA patients recruited, 17 represented ENDO and 15 OPEN. The intra-aneurysmal thrombus was removed during OPEN, but stayed intact after ENDO. The preoperative volume of the intra-aneurysmal thrombus was calculated from computed tomography images. Markers of coagulation and inflammation were studied preoperatively, at one, two, three, four and seven days and at three months postoperatively. RESULTS: Preoperative upregulation of F 1+2, TAT and D-dimer was evident in both groups. The volume of intra-aneurysmal thrombus correlated with CRP (beta = 0.62, p = 0.001), IL-6 (beta = 0.60, p = 0.001) and PAI-1 ag (beta = 0.51, p = 0.007). Surgery further enhanced inflammation, coagulation and fibrinolysis. IL-6 increased in both groups, but the increases of CRP and PIIINP were higher in the OPEN group. Postoperative CRP correlated with the intra-aneurysmal thrombus volume in the ENDO group. At three months D-dimer (p < 0.05) was higher than preoperatively in the ENDO, in contrast to the OPEN group. CONCLUSION: Preoperatively both prothrombotic and fibrinolytic mechanisms are activated in patients with AAA. Intraluminal thrombus induces prothrombotic and inflammatory interactions, which persist after endovascular aortic aneurysm repair.

Early elective conversion for failing EVAR.

BACKGROUND: The aim of the study was to assess the long term results of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms at the Helsinki University Central Hospital 1996-2004 with a special emphasis on elective conversion procedures and their outcome. METHODS: Treatment results and follow-up data of all 110 elective EVAR procedures performed in our institution were gathered prospectively and evaluated. RESULTS: Conversion to open surgery was performed in 23 (21%) of 110 EVAR patients. 30-day mortality after elective stent-graft deployment was 0% as it was also on elective conversions (n = 20). Secondary elective conversions were performed due to infection in two and after failing stent-graft treatment in 12 patients. Six of the conversions were performed primarily. Three urgent conversions (3% overall) were performed: two of these patients died, corresponding to an overall mortality of 9% (2/23) in all conversions. Five-year aneurysm-related mortality after EVAR among patients with elective conversion was 0% and 19% in patients with secondary procedures other than elective conversions. CONCLUSIONS: As conversions seem to be hazardous only when performed in urgent situations, elective conversion could be an alternative treatment method in complex failing first-generation stent-grafts as it may reduce mortality associated with urgent conversions or repeated attempts to maintain graft integrity with endovascular procedures.

The impact of adjuvant av-fistula on cuffed Femorocrural PTFE bypass grafting: flow and pressure response.

OBJECTIVE: The aim of the present study was to assess the effect of an adjuvant av-fistula on prosthetic bypass grafting and whether intraoperative flow measurements could predict patency and adverse events of cuffed femorocrural PTFE bypass with or without an av-fistula. METHODS: A total of 50 patients in need of vascular reconstruction for critical limb ischaemia (CLI) but with no suitable venous conduit were included. RESULTS: The flow values in patients with av-fistula were significantly higher (p=0.009) than in the group without the fistula but the higher flow values did not result in improved patency. The maximum flow velocity (Vmax) in the av-fistula group was significantly higher in the immediate postoperative period (p=0.04), but there was no difference in patency. When a flow value of 50 ml/min was used as a cut-off point, patients with a higher flow had significantly better immediate patency (p=0.025). CONCLUSION: The adjuvant av-fistula neither caused any adverse effects nor had any effect on patency.

Endovascular vs open AAA repair: similar effects on renal proximal tubular function.

AIM: To compare the effect of open and endovascular repair on renal function. MATERIALS AND METHODS: In a prospective, non-randomized study twenty-four abdominal aortic aneurysms (AAA) treatable with either method were repaired, 15 using endovascular device (ENDO group) and nine with open surgery with infrarenal aortic cross-clamping (OPEN group). All the patients had standardised general anaesthesia, intravascular fluid therapy and monitoring. Renal function tests and cardiovascular measurements were performed at predetermined intervals. RESULTS: N-acetyl-beta-D-glucosaminidase indexed to urinary creatinine (U-NAG/crea), a sensitive marker of renal proximal tubular damage, increased similarly in both groups at the end of surgery (two-way ANOVA, p < 0.05). No patient developed clinical renal impairment, on the contrary, creatinine clearance was increased, serum cystatin C (a sensitive marker of renal glomerular filtration) and serum creatinine concentration decreased at 24 hours postoperatively (Wilcoxon paired test, p < 0.05). Intraoperative blood loss and the amount of administered crystalloids were higher in the OPEN than in the ENDO group (Mann-Whitney U-test, p < 0.05). The cardiovascular measurements were comparable between the groups. The mean (SD) amount of radio-contrast media given was 3.1 (1.1) ml/kg in the ENDO group. CONCLUSIONS: Our results indicate that endovascular AAA repair does not protect renal proximal tubular function. A temporary renal tubular dysfunction was found both in open and in endovascular AAA repair which did not lead to permanent changes in renal function.

Endovascular treatment of aortic aneurysms in Finland: the first four years' experience.

BACKGROUND AND AIMS: In this study the results of endovascular treatment of aortic aneurysms in Finland are presented and compared to the results of the Eurostar registry. MATERIAL AND METHODS: A total of 229 patients with aortic aneurysm were treated in five different Finnish centres during 1996-2000. The data of these patients were collected prospectively by surgeon or interventional radiologist involved. During the same period of time 2464 patients were registered in the Eurostar registry. RESULTS: The procedure was performed successfully in 97% of patients in Finland, and the 30-day mortality was 0,9%. A graft limb thrombosis was detected in 9% of the patients in Finland. A permanent primary endoleak at the first 30-day control was seen in 23 patients (10%). During the follow-up 17 secondary endoleaks (7%) were detected. A secondary intervention was necessary in 26% of the patients. Three patients (1.3%) had late rupture of the abdominal aortic aneurysm. CONCLUSIONS: According to the Finnish short-time results, endovascular treatment of aortic aneurysms is safe and associated with relatively low morbidity and mortality. The mid-term results are more disappointing with relatively many graft thromboses and endoleaks, and a frequent need of secondary interventions.