Pekka-Sakari Aho

Arm vein conduit vs prosthetic graft in infrainguinal revascularization for critical leg ischemia

BACKGROUND One-piece great saphenous vein (GSV) is the conduit of choice in infrainguinal revascularizations for critical limb ischemia (CLI). Unfortunately, adequate length of usable GSV is not always available. Despite inferior patency rates compared with GSV, prosthetic and arm vein conduits are generally considered usable. The purpose of this study was to compare the outcome of infrainguinal arm vein and prosthetic bypass. MATERIAL AND METHODS We retrospectively reviewed 290 consecutive infrainguinal bypasses for CLI using arm vein conduit (n = 130) or prosthetic graft (n = 160) during January 2000 and December 2006 at our institution. The groups were compared for risk factors, indication for surgery, and runoff score. Survival, leg salvage, and patency rates were calculated with the Kaplan-Meier method. RESULTS Median surveillance time was 35 months (range 0-118 months). The age, gender, and usual risk factors were similar in arm vein and prosthetic groups, except cerebrovascular disease that was more common in the prosthetic group (P = .011). Indication for surgery was CLI. In the arm vein group, more than two-thirds (70.2%) of the procedures were for ischemic ulcer or gangrene, whereas in the prosthetic group the main indication was ischemic rest pain (51.3%). When the outcome of femoropopliteal bypasses was analyzed, the difference between groups was not statistically significant. However, in infrapopliteal revascularizations primary patency, assisted primary patency, and secondary patency rates at 3 years were significantly better in the arm vein group: 28.3% (SE +/- 6.3%) vs 9.6% (SE +/- 8.1%) (P = .031), 56.8% (SE +/- 6.6%) vs 10.4% (SE +/- 8.7%) (P = .000), and 57.4% (SE +/- 6.6) vs 11.2% (SE +/- 9.3%) (P = .000), respectively. Leg salvage and survival at 3 years were 75.0% (SE +/- 4.9%) vs 57.1% (SE +/- 8.8%) (P = .005) and 58.8% (SE +/- 5.1%) vs 39.5% (SE +/- 7.7%) (P = .007), respectively. CONCLUSION Arm vein conduits, even when spliced, are superior to prosthetic grafts in terms of midterm assisted primary patency, secondary patency, and leg salvage in infrapopliteal bypasses for CLI.

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.

The influence of the characteristics of ischemic tissue lesions on ulcer healing time after infrainguinal bypass for critical leg ischemia

OBJECTIVE Ulcer healing is a seldom reported outcome in studies of critical leg ischemia (CLI). The aim of this study was to analyze local factors affecting ulcer healing time after infrainguinal bypass surgery (IBS) for CLI Fontaine IV. METHODS In this prospective single center cohort study, 110 patients (113 legs) undergoing IBS due to CLI with ischemic tissue defects during year 2006 were followed prospectively for 1 year after the bypass. Ulcer location, duration, presence of gangrene, and the University of Texas wound classification (UTWCS) were determined at presentation. Healing time of the ischemic tissue defects, leg salvage, patency, and survival were calculated. The characteristics of the ischemic tissue lesions and patient comorbidities were analyzed to determine risk factors for adverse outcome. RESULTS Complete ulcer healing (+/-SE) was achieved in 74% +/- 5% of the legs 12 months after IBS. Median ulcer healing time was 186 days (range, 11 to >365 days). Leg salvage, secondary patency, and survival at 12 months were 87% +/- 3%, 82% +/- 4%, and 76% +/- 5%, respectively. Amputation-free survival with healed ulcers was attained in 55% at 12 months. Ischemic tissue lesions located in the mid- and hindfoot had significantly prolonged ulcer healing time (hazard ratio [HR] 0.4, 95% confidence interval [CI] 0.1 to 0.9, P = .044). None of the UTWCS classes predicted either ulcer healing time or leg salvage. Median ulcer duration before IBS was 68 days, range, 6 to 1154 days. Ulcer duration did not correlate with ulcer healing time (Spearman r = 0.138, P = .267). Ischemic ulcers with gangrene were not associated with prolonged ulcer healing time (P = .353). CONCLUSION The location of the ischemic tissue lesions influences ulcer healing time. According to our study UTWCS can be used as descriptive classification of ischemic ulcers but it does not predict the ulcer healing time or leg salvage after infrainguinal bypass surgery.

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.

Poor Inter-observer Agreement on the TASC II Classification of Femoropopliteal Lesions *

OBJECTIVES This study aims to evaluate the reproducibility of femoropopliteal TASC II classification and to analyse the influence of an educational intervention on inter-observer agreement. DESIGN This is a validation study. MATERIALS This study included 200 consecutive angiograms of femoropopliteal arterial lesions. METHODS Seven investigators evaluated the first 100 angiograms, independently aided by the available TASC guide. Thereafter, the intervention included a discussion of the 25 most problematic cases, initially by a panel of 22 vascular surgeons, and later by the seven investigators to clarify grading principles. In the second stage, the 100 remaining cases were evaluated independently. A multi-rater variation of Brennan and Predigers free-marginal kappa (kappa(free)) was used to calculate inter-observer agreement. RESULTS There were lesions not fitting any of the TASC classes. Total agreement among all seven investigators was reached in 7% and 19% of the cases before and after the intervention, respectively. In the first stage, kappa(free) was 0.32 between all observers (range between two observers kappa(free)=0.11-0.54). The intervention increased the agreement to kappa(free)=0.49 (range: 0.20-0.56). Agreement between the two observers was 38-69% (mean 49%) before the intervention and 51-73% (mean 61%) thereafter. CONCLUSIONS TASC II classification for femoropopliteal lesions allows individual interpretations, and the common use of this classification as a basis for decision making and reporting outcomes could therefore be questioned.

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.

The consequences of an outbreak of multidrug-resistant Pseudomonas aeruginosa among patients treated for critical leg ischemia.

OBJECTIVE This retrospective matched case-control study evaluated the consequences of multidrug-resistant Pseudomonas aeruginosa (MDR Pa) in critical leg ischemia (CLI) patients treated with infrainguinal bypass surgery (IBS). METHODS An outbreak of MDR Pa occurred on our vascular surgical ward during a 13-month period. Bacteria cultures positive for MDR Pa were obtained from 129 patients, and 64 CLI patients treated with IBS formed the study group. A control group of 64 was retrospectively matched from MDR Pa-negative patients treated with IBS in the same unit according to sex, age, presence of diabetes, Fontaine class, graft material, and site of the distal anastomosis. The most frequent sites of initial positive MDR Pa culture were the incisional wound in 30 (47%) and ischemic ulcer in 23 (36%). Median time between the positive MDR Pa-culture and IBS was 14 days (range, 56 days pre-IBS to 246 days post-IBS). Graft patency, survival, leg salvage, and amputation-free survival were assessed. RESULTS One-year amputation-free survival (+/- standard error) was 52% +/- 6% in the MDR Pa group vs 75% +/- 5% in the control group (P = .02). Five-year amputation-free survival was 29% +/- 6% in the MDR Pa group and 32% +/- 6% in the control group (P = .144). For MDR Pa and control groups, the 1-year survival was 69% +/- 6% and 82% +/- 5% (P = .063), respectively, and 5-year survival was 36% +/- 6% and 36% +/- 6% (P = .302), respectively. For the MDR Pa and control groups, leg salvage was 79% +/- 5% and 92% +/- 4% at 1 year (P = .078) and 73% +/- 7% and 87% +/- 5% at 5 years (P = .126), respectively. The overall secondary patency rate at 1 year was 72% +/- 7% in the MDR Pa group vs 81% +/- 6% in the control group (P = .149). Local wound surgery was more frequent in MDR Pa patients than in controls (P = .002). CONCLUSIONS The MDR Pa outbreak was associated with a decreased short-term amputation-free survival after IBS for CLI in patients with positive MDR Pa culture. The potential risks of MDR Pa should be seriously considered whenever a positive culture is obtained in a vascular patient with CLI.