Bovine pericardial patch: A good alternative in femoral angioplasty.

OBJECTIVE: Bovine pericardial patch (BPP) is currently used in femoral angioplasty as an alternative for autologous vein patch (AVP), but studies comparing the results of the two methods are scarce. In this retrospective study, we aimed to discover the differences between BPP and AVP closure in long-term durability. METHODS: This study consisted of all femoral endarterectomies with BPP closure performed in Helsinki University Hospital from January 1, 2014, to December 31, 2017. For comparison, the same number of consecutive patients who underwent femoral endarterectomy with AVP closure from January 1, 2014, to October 16, 2016, were reviewed. Follow-up ended December 31, 2020. The mean follow-up was 19 months (range, 0-74 months) in the BPP group and 22 months (range, 0-79 months) in the AVP group. The primary endpoint was primary patency. Secondary endpoints were restenosis at patch site detected by imaging or perioperatively, patch rupture, and deep surgical wound infection. Propensity score analysis was performed for adjustment of differences between the AVP and BPP groups. RESULTS: Overall primary patency was superior in the AVP group compared with the BPP group: at 1 year, 96.5% vs 85.0% and at 5 years, 83.0% vs 72.3% (P = .04). In propensity score-matched pairs (n = 92), no difference was found between the groups in primary patency: 95.7% and 95.7% at 1 year and 92.5% and 78.6% at 5 years (P = .861) or in freedom from restenosis: 100% and 100% at 1 year and 89.1% and 84.0% at 5 years (P = .057). Deep wound infections occurred slightly more often after BPP closure (8%) than after AVP closure (4%), but the difference was not statistically significant (P = .144). There were no patch ruptures in the BPP group, but in the AVP group, there were five ruptures (3.5%) (P = .024). CONCLUSIONS: BPP is compatible to AVP in femoral endarterectomy in patency and can be regarded as the safer choice considering the risk of patch rupture.

Impact of the COVID-19 pandemic on the management of gallstone surgery: A Swedish population-based study.

BACKGROUND: The SARS-CoV-2 pandemic has had a significant impact on healthcare delivery. As resources are reallocated, surgery for benign conditions such as gallstone disease is often given low priority. We do not know how this has affected the risk of patients with uncomplicated gallstone disease to develop acute cholecystitis, biliary pancreatitis, or obstructive jaundice. METHODS: The study was based on the population-based Swedish Register of Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography. The period prior to the first cases of COVID-19 in Sweden, that is, April 2015-March 2020, was compared to the period April 2020-March 2021 during the pandemic. Stratification was made for factors potentially related to priority decisions. RESULTS: Altogether, 78,211 procedures were performed during the period of the study. The ratio of procedures performed during April 2020-March 2021 in the previous 5 years was 0.960 (p = 0.113). The ratio of procedures on patients aged <65 years was 0.945 (p = 0.008), on patients aged 65-80 years was 0.964 (p = 0.423), on patients aged >80 years was 1.336 (p = 0.025), on men was 1.001 (p = 0.841), on women was 0.934 (p = 0.006), on procedures completed laparoscopically was 0.964 (p = 0.190), on procedures completed with open approach was 0.659 (p = 0.044), on acute procedures was 1.218 (p = 0.016), on planned procedures was 0.791 (p < 0.001), on procedures performed for biliary colic was 0.808 (p < 0.001), on procedures performed for acute cholecystitis was 1.274 (p = 0.012), for biliary pancreatitis was 1.192 (p = 0.037), and for obstructive jaundice was 1.366 (p = 0.008). CONCLUSIONS: The COVID-19 has had a great impact on how gallstone surgery has been organized over the last 2 years. The decreased number of planned procedures probably reflects the reallocation of resources during the pandemic. However, whether the increasing number of acute procedures is the result of postponed planned surgery or a continuation of a long-term trend toward more acute surgery remains unanswered. Further studies are needed to assess and evaluate how this has affected public health and health economics.

Procurement and Evaluation of Hepatocytes for Transplantation From Neonatal Donors After Circulatory Death.

Hepatocyte transplantation is a promising treatment for liver failure and inborn metabolic liver diseases, but progress has been hampered by a scarcity of available organs. Here, hepatocytes isolated from livers procured for a neonatal hepatocyte donation program within a research setting were assessed for metabolic function and suitability for transplantation. Organ donation was considered for infants who died in neonatal intensive care in the Stockholm region during 2015-2021. Inclusion was assessed when a decision to discontinue life-sustaining treatment had been made and hepatectomy performed after declaration of death. Hepatocyte isolation was performed by three-step collagenase perfusion. Hepatocyte viability, yield, and function were assessed using fresh and cryopreserved cells. Engraftment and maturation of cryopreserved neonatal hepatocytes were assessed by transplantation into an immunodeficient mouse model and analysis of the gene expression of phase I, phase II, and liver-specific enzymes and proteins. Twelve livers were procured. Median warm ischemia time (WIT) was 190 [interquartile range (IQR): 80-210] minutes. Median viability was 86% (IQR: 71%-91%). Median yield was 6.9 (IQR: 3.4-12.8) x106 viable hepatocytes/g. Transplantation into immunodeficient mice resulted in good engraftment and maturation of hepatocyte-specific proteins and enzymes. A neonatal organ donation program including preterm born infants was found to be feasible. Hepatocytes isolated from neonatal donors had good viability, function, and engraftment despite prolonged WIT. Therefore, neonatal livers should be considered as a donor source for clinical hepatocyte transplantation, even in cases with extended WIT.

Competing Risk Analysis of the Impact of Pedal Arch Status and Angiosome-Targeted Revascularization in Chronic Limb-Threatening Ischemia.

BACKGROUND: In the context of chronic limb-threatening ischemia, the prognostic impact of angiosome-targeted revascularization and of the status of the pedal arch are debated. METHODS: This series includes 580 patients who underwent endovascular (n = 407) and surgical revascularization (n = 173) of the infrapopliteal arteries for chronic limb-threatening ischemia associated with foot ulcer or gangrene. The risk of major amputation after infrapopliteal revascularization was assessed by a competing risk approach. A subanalysis was made separately for patients who underwent endovascular or open surgical revascularization. RESULTS: At 2 years, survival was 65.1% and leg salvage was 76.1%. Multivariable competing risk analysis showed that C-reactive protein ≥10 mg/dL, diabetes, rheumatoid arthritis, increased number of affected angiosomes, and the incomplete or total absence of pedal arch compared with complete pedal arch (CPA) were independent predictors of major amputation after infrapopliteal revascularization. Multivariable analysis showed increasing risk estimates of major amputation in patients with incomplete (subdistribution hazard ratio [SHR], 2.131; 95% confidence interval [95% CI], 1.282-3.543) and no visualized pedal arch (SHR, 3.022; 95% CI, 1.553-5.883) compared with CPA. Pedal arch was important even if angiosome-targeted revascularization was achieved: Angiosome-directed revascularization in presence of CPA had a lower risk of major amputation (adjusted SHR, 0.463; 95% CI, 0.240-0.894) compared with angiosome-directed revascularization without CPA. In the subanalysis, among patients who underwent endovascular revascularization, CPA (SHR, 0.509; 95% CI, 0.286-0.905) and angiosome-targeted revascularization (SHR, 0.613; 95% CI, 0.394-0.956) were associated with a lower risk of major amputation. CONCLUSIONS: Competing risk analysis showed that a patent pedal arch had significant impact on leg salvage and that the subset of patients undergoing endovascular procedure may most benefit of an angiosome-targeted revascularization.

Angiosome-targeted infrapopliteal endovascular revascularization for treatment of diabetic foot ulcers.

OBJECTIVE: Because of the prolonged healing time of diabetic foot ulcers, methods for identifying ways to expedite the ulcer healing process are needed. The angiosome concept delineates the body into three-dimensional blocks of tissue fed by specific source arteries. The aim of this study was to evaluate the benefit of infrapopliteal endovascular revascularization guided by an angiosome model of perfusion in the healing process of diabetic foot ulcers. METHODS: A total of 250 consecutive legs with diabetic foot ulcers in 226 patients who had undergone infrapopliteal endovascular revascularization in a single center were evaluated. Patient records and periprocedural leg angiograms were reviewed. The legs were divided into two groups depending on whether direct arterial flow to the site of the foot ulcer based on the angiosome concept was achieved (direct group) or not achieved (indirect group). Ulcer healing time was compared between the two groups. A propensity score was used for adjustment of differences in pretreatment covariables in multivariate analysis and for 1:1 matching. RESULTS: Direct flow to the angiosome feeding the ulcer area was achieved in 121 legs (48%) compared with indirect revascularization in 129 legs. Foot ulcers treated with angiosome-targeted infrapopliteal percutaneous transluminal angioplasty healed better. The ulcer healing rate was mean (standard deviation) 72% (5%) at 12 months for the direct group compared with 45% (6%) for the indirect group (P < .001). When adjusted for propensity score, the direct group still had a significantly better ulcer healing rate than the indirect group (hazard ratio, 1.97; 95% confidence interval, 1.34-2.90; P = .001). CONCLUSIONS: Attaining a direct arterial flow based on the angiosome model of perfusion to the foot ulcer appears to be important for ulcer healing in diabetic patients.

Outcome of infrainguinal single-segment great saphenous vein bypass for critical limb ischemia is superior to alternative autologous vein bypass, especially in patients with high operative risk.

BACKGROUND: Single-segment great saphenous vein (ssGSV) is the conduit of choice in infrainguinal bypass for critical limb ischemia (CLI). The aim of this study was to assess results of other autologous vein grafts and risk factors for graft stenosis development and graft failure. The purpose was also to evaluate outcome of patients with high operative risk undergoing infrainguinal alternative autologous vein bypass for CLI. METHODS: We retrospectively reviewed 1,109 consecutive infrainguinal bypasses performed between 2000 and 2007 for CLI. Rate and type of operations needed to maintain graft patency were evaluated. Outcome of different types of vein grafts in terms of primary patency, assisted primary patency, secondary patency, and limb salvage was assessed using Kaplan-Meier method. Predictors of poor outcome as well as patient- and graft-related risk factors for graft revision and graft failure were analyzed using multivariate analysis. RESULTS: Median follow-up period was 37 (0-121) months. Primary patency, assisted primary patency, secondary patency, and limb salvage at 1 and 3 years were significantly better in ssGSV graft group than in alternative autologous vein graft (AAVG) group-74.4% and 67.1% versus 53.7% and 42.0% (P < 0.0001), 82.8% and 78.2% versus 67.2% and 57.8% (P < 0.0001), 84.8% and 80.8% versus 69.9% and 61.4% (P < 0.0001), and 88.9% and 86.9% versus 83.0% and 77.2% (P < 0.0001), respectively. In multivariate analysis, non-ssGSV graft was the only independent risk factor for the graft stenosis development (relative risk [RR]: 2.62, 95% confidence interval [CI]: 1.56-4.38, P < 0.0001), for graft occlusion (RR: 2.27, 95% CI: 1.52-3.40, P < 0.0001), and for graft failure (stenosis or occlusion) (RR: 2.00, 95% CI: 1.39-2.88, P < 0.0001). Revision rate of non-ssGSV conduits was higher than that of ssGSV grafts (18% vs. 12%, P = 0.007). High-risk patients (age of >80 years, coronary artery disease, estimated glomerular filtration rate of <30 mL/min/1.73 m(2)) who underwent bypass with arm vein or spliced vein had extremely poor outcome (1-year leg salvage rate and survival rate of 71.4% and 28.6%, respectively). CONCLUSION: The ssGSV graft is superior to any other autologous vein graft in terms of midterm patency and leg salvage. It also needs less maintenance procedures than AAVGs. Non-ssGSV graft is independent predictor of both graft stenosis development and graft failure. Acceptable patency and leg salvage rates can also be achieved with AAVGs. However, patients with high operative risk and non-ssGSV graft bypass have poor outcome.

Tertiary patency as a measure of active revascularization policy for leg salvage.

BACKGROUND: An active surgical strategy to save lower limbs of patients with critical leg ischemia includes not only infrainguinal bypass surgery but also repeated surgery when needed. A failed infrainguinal bypass often threatens viability of the patient's legs, at which point a redo bypass procedure with a new graft may be the only alternative to major amputation. We assessed tertiary patency, defined as the whole period of time with a patent infrainguinal graft in a leg, to illustrate future potential of limb salvage surgery after a failed bypass. METHODS: A total of 593 patients with critical leg ischemia and tissue defects (Fontaine IV) who underwent infrainguinal bypass surgery between January 2000 and December 2005 at our institution were included in this retrospective study. RESULTS: Secondary and tertiary patency rates were 95 ± 1% and 96 ± 3% at 1 month, 75 ± 2% and 82 ± 2% at 1 year, and 61 ± 2% and 70 ± 3% at 5 years, respectively, p = 0.003. Leg salvage rate was 94 ± 1% at 1 month, 83 ± 2% at 1 year, and 78 ± 2% at 5 years. There was no significant difference between leg salvage and tertiary patency rates, p = 0.281. CONCLUSION: Tertiary patency rate was higher than the secondary patency rate. This result might reflect active limb salvage surgery with satisfactory results. The absence of a gap between tertiary patency and leg salvage rates indicates the importance of a patent infrainguinal bypass graft to save lower limbs of patients with ischemic tissue defects.

Infrapopliteal percutaneous transluminal angioplasty versus bypass surgery as first-line strategies in critical leg ischemia: a propensity score analysis.

INTRODUCTION: Recently, endovascular revascularization (percutaneous transluminal angioplasty [PTA]) has challenged surgery as a method for the salvage of critically ischemic legs (CLI). Comparison of surgical and endovascular techniques in randomized controlled trials is difficult because of differences in patient characteristics. To overcome this problem, we adjusted the differences by using propensity score analysis. MATERIALS AND METHODS: The study cohort comprised 1023 patients treated for CLI with 262 endovascular and 761 surgical revascularization procedures to their crural or pedal arteries. A propensity score was used for adjustment in multivariable analysis, for stratification, and for one-to-one matching. RESULTS: In the overall series, PTA and bypass surgery achieved similar 5-year leg salvage (75.3% vs 76.0%), survival (47.5% vs 43.3%), and amputation-free survival (37.7% vs 37.3%) rates and similar freedom from any further revascularization (77.3% vs 74.4%), whereas freedom from surgical revascularization was higher after bypass surgery (94.3% vs 86.2%, P < 0.001). In propensity-score-matched pairs, outcomes did not differ, except for freedom from surgical revascularization, which was significantly higher in the bypass surgery group (91.4% vs 85.3% at 5 years, P = 0.045). In a subgroup of patients who underwent isolated infrapopliteal revascularization, PTA was associated with better leg salvage (75.5% vs 68.0%, P = 0.042) and somewhat lower freedom from surgical revascularization (78.8% vs 85.2%, P = 0.17). This significant difference in the leg salvage rate was also observed after adjustment for propensity score (P = 0.044), but not in propensity-score-matched pairs (P = 0.12). CONCLUSIONS: When feasible, infrapopliteal PTA as a first-line strategy is expected to achieve similar long-term results to bypass surgery in CLI when redo surgery is actively utilized.

Finnvasc score and modified Prevent III score predict long-term outcome after infrainguinal surgical and endovascular revascularization for critical limb ischemia.

BACKGROUND: Estimation of the risk of adverse long-term outcome is of paramount importance in the treatment of critical limb ischemia (CLI). METHODS: We evaluated the accuracy of two specific risk score systems, the Finnvasc score and the modified Prevent III (mPIII) score, in 1425 CLI patients who underwent unilateral, infrainguinal surgical (47.6%) or endovascular (52.4%) revascularization. The receiver operating characteristic (ROC) curve analysis was used to estimate the predictive value of these risk scoring methods. RESULTS: The area under the ROC curve of Finnvasc score for prediction of 30-day amputation was 0.609 (95% confidence interval [CI] 0.549-0.677) and of mPIII score 0.533 (95% CI 0.457-0.609). The area under ROC curve of Finnvasc score for prediction of 30-day amputation-free survival was 0.622 (95% CI 0.573-0.671) and of mPIII score 0.588 (95% CI 0.533-0.642). The area under the ROC curve of Finnvasc score for prediction of 1-year amputation-free survival was 0.630 (95% CI 0.597-0.663, P<.0001) and of mPIII score 0.634 (95% CI 0.600-0.667, P<.0001). Finnvasc score predicted leg salvage (relative risk [RR] 1.431, 95% CI 1.319-1.551), survival (RR 1.233, 95% CI 1.116-1.363), and amputation-free survival (RR 1.422, 95% CI 1.319-1.534). mPIII score also predicted leg salvage (RR 1.190, 95% CI 1.108-1.277), survival (RR 1.245, 95% CI 1.193-1.300), and amputation-free survival (RR 1.223, 95% CI 1.176-1.272). CONCLUSIONS: Finnvasc and modified PIII risk scoring methods predict long-term outcome of patients undergoing infrainguinal revascularization for CLI. Finnvasc score seems to perform well also in predicting immediate postoperative outcome.

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.

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.

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.

Airborne PCB as a contamination risk on freeze-drying of sediment.

In a study of polychlorinated biphenyls (PCB) in freeze-dried sediments from Swedish lakes, the samples were found to contain unexpectedly high concentrations of PCBs. In one of the lakes (Björken), e.g. the concentration of PCB-28 was found to be 189 ng/g dw after freeze-drying compared to 7 ng/g dw after air-drying of the sediment and therefore our hypothesis was that the contamination had occurred during the freeze-drying procedure. Hence, a dry reference sediment (RS) was used in order to identify potential sources of PCB contamination. The investigation included freeze-drying of the dry RS in five different laboratories, exposure to the air in the freeze-drying room, storage at room temperature and air-drying in a certain fume hood and in a laminar flow clean bench. The pattern and concentrations of PCBs detected in the exposed RS were strongly influenced by low chlorinated PCB congeners under all of these conditions with exception for air-drying in the fume hood. Storage in the laboratory air resulted in a slight elevation in the concentrations of low chlorinated PCB congeners, whereas higher concentrations of all PCB congeners were observed after freeze-drying. In all experiments the contamination appeared to be due to adsorption of PCB from the laboratory air. On the basis of these findings we recommend that reference material be subjected to the entire procedure, including sample preparation, in order to monitor contamination and that a procedure involving solvent extraction of wet sediment samples is used, whenever possible, instead of procedures involving dry samples.