Five-Year Outcomes of the SuperB Trial: A Multicenter Randomized Controlled Trial Comparing Heparin-Bonded Endograft to Surgical Femoropopliteal Bypass.

OBJECTIVE: This study aims to compare the 5-year outcomes of endoluminal bypass (EB) using heparin-bonded self-expanding covered stents versus bypass surgery for extensive femoropopliteal disease, including technical and clinical outcomes and health status. BACKGROUND: The surgical femoropopliteal bypass was the gold standard to treat peripheral arterial disease (PAD) for decades; however, endovascular treatment modalities are now recommended for most femoropopliteal lesions. One-year data of a randomized controlled trial comparing EB with surgical bypass (SB) have shown a faster recovery, less morbidity, and comparable patency rates between the two techniques. To date, long-term randomized controlled data regarding both techniques are lacking. METHODS: Five-year results of a multicenter randomized controlled trial comparing EB with SB in patients with femoropopliteal artery disease were evaluated based on intention-to-treat and per-protocol analyses. RESULTS: At 5-year follow-up, primary, primary-assisted, and secondary patency rates were 36.2%, 52.4%, and 68.1% for EB and 49.4%, 72.2%, and 77.8% for SB, respectively (p=0.608). Freedom from target lesion revascularization (fTLR) was 34.1% for EB and 57.6% for SB (p=0.365). In both groups, the ankle-brachial index, Rutherford classification, and walking distance significantly improved compared with baseline without differences between groups at follow-up. Freedom from major amputation rate was 92.6% in the EB group and 96.2% in the SB group (p=0.361). The 36-Item Short-Form Health Survey showed no significant differences between groups. CONCLUSION: Treatment of extensive femoropopliteal disease with self-expanding covered stents provides comparable clinical-related and health-related questionnaire outcomes when compared with SB through 5 years of follow-up. However, the EB is related to a higher number of reinterventions. CLINICAL IMPACT: This present study is the first to report five-year outcomes comparing an endoluminal (EB) using heparin-bonded self-expanding covered stents with surgical bypass (SB) for long and complex femoropopliteal disease. Although the advantages of treatment with EB are mostly seen in the early period after treatment, the outcomes support the use of EB for this indication and seems to be a valid and safe alternative for bypass surgery. Future trials comparing various endovascular strategies may provide further guidance for the development of an evidence-based treatment algorithm.

Clinical impact of assessing thrombus age using magnetic resonance venography prior to catheter-directed thrombolysis.

OBJECTIVES: Magnetic resonance venography (MRV) is underutilized in the evaluation of thrombus properties prior to endovascular treatment but may improve procedural outcomes. We therefore investigated the clinical impact of using a dedicated MRV scoring system to assess thrombus characteristics prior to endovascular intervention for iliofemoral deep vein thrombosis (DVT). METHODS: This is a post hoc analysis of data from the CAVA trial ( Clinicaltrials.gov :NCT00970619). MRV studies of patients receiving ultrasound-accelerated catheter-directed thrombolysis (CDT) for iliofemoral DVT were reviewed. Thrombus age-related imaging characteristics were scored and translated into an overall score (acute, subacute, or old). MRV scores were compared to patient-reported complaints. MRV-scored groups were compared for CDT duration and success rate. RESULTS: Fifty-six patients (29 men; age 50.8 ± 16.4 years) were included. Using MRV, 27 thrombi were classified acute, 17 subacute, and 12 old. Based on patient-reported complaints, 11 (91.7%) of these old thrombi would have been categorized acute or subacute, and one (3.7%) of the acute thrombi as old. Average duration of CDT to > 90% restored patency differed significantly between groups (p < 0.0001): average duration was 23 h for acute thromboses (range: 19-25), 43 h for subacute (range: 41-62), and 85 h for old thromboses (range: 74-96). CDT was almost eleven times more successful in thromboses characterized as acute and subacute compared to old thromboses (OR: 10.7; 95% CI 2.1-55.5). CONCLUSION: A dedicated MRV scoring system can safely discriminate between acute, subacute, and old thromboses. MRV-based selection is predictive of procedural duration and success rate and can help avoid unnecessary complications. KEY POINTS: • Thrombus age, characterized by MRV as acute, subacute, and old, can predict CDT duration and probability of success. • Accurate pre-interventional MRV-based thrombus aging has the potential to facilitate identification of eligible patients and may thus prevent CDT-related complications.

CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis on Preventing Post-Thrombotic Syndrome) Trial: Long-Term Follow-Up Results.

Background The CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis Versus Anticoagulation for the Prevention of Post-Thrombotic Syndrome) trial did not show a reduction of post-thrombotic syndrome (PTS) after additional ultrasound-accelerated catheter-directed thrombolysis in patients with acute iliofemoral deep vein thrombosis at 1-year follow-up. This prespecified analysis of the CAVA trial aimed to determine the impact of additional thrombolysis on outcomes of PTS at long-term follow-up. Methods and Results Patients aged 18 to 85 years with a first-time acute iliofemoral deep vein thrombosis were included and randomly assigned (1:1) to either standard treatment plus ultrasound-accelerated catheter-directed thrombolysis or standard treatment alone. The primary outcome was the proportion of PTS (Villalta score ≥5 on 2 occasions ≥3 months apart or venous ulceration) at the final follow-up visit. Additionally, PTS according to the International Society on Thrombosis and Haemostasis (ISTH) consensus definition was assessed to allow external comparability. Major bleedings were the main safety outcome. At a median follow-up of 39.0 months (interquartile range, 23.3-63.8), 120 patients (79.8%) participated in the final follow-up visit: 62 from the intervention group and 58 from the standard treatment group. PTS developed in 19 (30.6%) versus 26 (44.8%) patients, respectively (odds ratio [OR], 0.54; 95% CI, 0.26 to 1.15 [P=0.11]), with an absolute difference between groups of -14.2% (95% CI, -32.0% to 4.8%). Using the ISTH consensus definition, a significant reduction in PTS was observed (29 [46.8%] versus 40 [69.0%]) (OR, 0.40; 95% CI, 0.19-0.84 [P=0.01]) with an absolute difference between groups of -22.2% (95% CI, -39.8% to -2.8%). No new major bleedings occurred following the 12-month follow-up. Conclusions The impact of additional ultrasound-accelerated catheter-directed thrombolysis on the prevention of PTS was found to increase with time. Although this study was limited by its sample size, the overall findings indicate a reduction of mild PTS without impact on quality of life. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00970619.

Association of Successful Ultrasound-Accelerated Catheter-Directed Thrombolysis with Postthrombotic Syndrome: A Post Hoc Analysis of the CAVA Trial.

BACKGROUND: The CAVA trial did not show the anticipated risk reduction for postthrombotic syndrome (PTS) after thrombus removal via additional ultrasound-accelerated catheter-directed thrombolysis (UACDT) in patients with acute iliofemoral deep vein thrombosis (IFDVT). Difficulties in achieving an effective degree of recanalization through thrombolysis may have influenced outcomes. We therefore assessed whether successful UACDT (restored patency ≥ 90%) did reduce the development of PTS. METHODS: This CAVA trial post hoc analysis compared the proportion of PTS at 1-year follow-up between patients with successful UACDT and patients that received standard treatment only. In addition, clinical impact as well as determinants of successful thrombolysis were explored. RESULTS: UACDT was initiated in 77 (50.7%) patients and considered successful in 41 (53.2%, interrater agreement κ = 0.7, 95% confidence interval 0.47-0.83). PTS developed in 15/41 (36.6%) patients in the successful UACDT group versus 33/75 (44.0%) controls (p = 0.44). In this comparison, successful UACDT was associated with lower Venous Clinical Severity Score (3.50 ± 2.57 vs. 4.82 ± 2.74, p = 0.02) and higher EuroQOL-5D (EQ-5D) scores (40.2 ± 36.4 vs. 23.4 ± 34.4, p = 0.01). Compared with unsuccessful UACDT, successful UACDT was associated with a shorter symptom duration at inclusion (p = 0.05), and higher rates of performed adjunctive procedures (p < 0.001) and stent placement (p < 0.001). CONCLUSION: Successful UACDT was not associated with a reduced proportion of PTS 1 year after acute IFDVT compared with patients receiving standard treatment alone. There was, however, a significant reduction in symptom severity and improvement of generic quality of life according to the EQ-5D. Better patient selection and optimization of treatment protocols are needed to assess the full potential of UACDT for the prevention of PTS. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number, NCT00970619.

Ultrasound-accelerated catheter-directed thrombolysis versus anticoagulation for the prevention of post-thrombotic syndrome (CAVA): a single-blind, multicentre, randomised trial.

BACKGROUND: Early thrombus removal might prevent post-thrombotic syndrome by preserving venous function and restoring flow. Previous trials comparing additional catheter-directed thrombolysis to standard treatment showed conflicting outcomes. We aimed to assess the benefit of additional ultrasound-accelerated catheter-directed thrombolysis for the prevention of post-thrombotic syndrome compared with standard therapy in patients with iliofemoral deep-vein thrombosis. METHODS: We did a multicentre, randomised, single-blind, allocation-concealed, parallel group, superiority trial in 15 hospitals in the Netherlands. Patients aged 18-85 years with a first-time acute iliofemoral deep-vein thrombosis and symptoms for no more than 14 days were randomly assigned (1:1) to either standard treatment with additional ultrasound-accelerated catheter-directed thrombolysis or standard treatment alone. Randomisation was done with a web-based automatic programme and a random varying block size (2-12), stratified by age and centre. Standard treatment included anticoagulant therapy, compression therapy (knee-high elastic compression stockings; 30-40 mmHg), and early ambulation. Additional ultrasound-accelerated catheter-directed thrombolysis was done with urokinase with a starting bolus of 250 000 international units (IU) in 10 mL NaCl followed by a continuous dose of 100 000 IU/h for a maximum of 96 h through the Ekos Endowave-system. Adjunctive percutaneous transluminal angioplasty, thrombosuction, or stenting was performed at the discretion of the physician who performed the intervention. The primary outcome was the proportion of patients with post-thrombotic syndrome at 12 months diagnosed according to the original Villalta criteria-a Villalta-score of at least 5 on two consecutive occasions at least 3 months apart or the occurrence of venous ulceration-and was assessed in a modified intention-to-treat population of all randomly assigned patients who passed screening and started treatment. The safety analysis was assessed in the same modified intention-to-treat population. This study is complete and is registered at ClinicalTrials.gov, NCT00970619. FINDINGS: Between May 28, 2010, and Sept 18, 2017, 184 patients were randomly assigned to either additional ultrasound-accelerated catheter-directed thrombolysis (n=91) or standard treatment alone (n=93). Exclusion because of screening failure or early withdrawal of informed consent resulted in 77 patients in the intervention group and 75 in the standard treatment group starting allocated treatment. Median follow-up was 12·0 months (IQR 6·0-12·0). 12-month post-thrombotic syndrome occurred in 22 (29%) patients allocated to additional treatment versus 26 (35%) patients receiving standard treatment alone (odds ratio 0·75 [95% CI 0·38 to 1·50]; p=0·42). Major bleeding occurred in four (5%) patients in the intervention group, with associated neuropraxia or the peroneal nerve in one patient, and no events in the standard treatment group. No serious adverse events occurred. None of the four deaths (one [1%] in the intervention group vs three [4%] in the standard treatment group) were treatment related. INTERPRETATION: This study showed that additional ultrasound-accelerated catheter-directed thrombolysis does not change the risk of post-thrombotic syndrome 1 year after acute iliofemoral deep-vein thrombosis compared with standard therapy alone. Although this trial is inconclusive, the outcome suggests the possibility of a moderate beneficial effect with additional ultrasound-accelerated catheter-directed thrombolysis. Further research is therefore warranted to better understand this outcome in the context of previous trials, preferably by combining the available evidence in an individual patient data meta-analysis. FUNDING: The Netherlands Organisation for Health Research and Development (ZonMw), Maastricht University Medical Centre, BTG-Interventional Medicine.

1-Year Results of a Multicenter Randomized Controlled Trial Comparing Heparin-Bonded Endoluminal to Femoropopliteal Bypass.

OBJECTIVES: This study sought to compare heparin-bonded endografts with femoropopliteal bypass, including quality of life, using general health and disease-specific questionnaires as well as patency rates. BACKGROUND: Endovascular treatment continues to advance and is gaining acceptance as primary treatment for long occlusive or stenotic lesions in the superficial femoral artery. Heparin-bonded expanded polytetrafluoroethylene endografts have been related to outcomes comparable to bypass surgery, but this has not been tested in a randomized fashion. METHODS: A multicenter randomized-controlled trial was performed comparing femoropopliteal bypass with heparin-bonded expanded polytetrafluoroethylene endografts. Data were analyzed on an intention-to-treat and per-protocol manner. RESULTS: A total of 129 patients were randomized and 125 patients were treated, 63 in the endoluminal and 62 in the surgical group (42 venous, 20 prosthetic). Enrollment was terminated before reaching the predefined target number for patency. Baseline characteristics and anatomical data were similar. Patients were treated for critical limb ischemia in 38.1% and 32.2% in the endoluminal and surgical arms, respectively. Mean lesion length was 23 cm in both groups and lesions were largely TransAtlantic Inter-Society Consensus II D. Hospitalization time and 30-day morbidity were significantly lower in the endoluminal group, without differences in serious adverse events (n = 5 each; surgical: 4 venous and 1 polytetrafluoroethylene bypass). There were no significant differences in Rutherford category between groups at any time point. At 30 days the endoluminal group showed a greater improvement in quality-of-life scores. At 1 year, these differences had largely disappeared and no differences in primary (endoluminal: 64.8%; surgical: 63.6%), assisted primary (endoluminal: 78.1%; surgical: 79.8%), secondary patency (endoluminal: 85.9%; surgical: 83.3%), and target vessel revascularization (endoluminal: 72.1%; surgical: 71.0%) were observed. Limb salvage rate was 100% in both groups. CONCLUSIONS: Heparin-bonded endoluminal bypass for long segment lesions shows promising results (less morbidity, faster recovery, and improvement in quality of life with indistinguishable patency rates at 1 year) compared with surgical bypass. Long-term results have to be awaited.

Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA).

Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associated with poor prognosis, particularly in high-risk patients. The cornerstones in the management of complicated IAIs are timely effective source control with appropriate antimicrobial therapy. Empiric antimicrobial therapy is important in the management of intra-abdominal infections and must be broad enough to cover all likely organisms because inappropriate initial antimicrobial therapy is associated with poor patient outcomes and the development of bacterial resistance. The overuse of antimicrobials is widely accepted as a major driver of some emerging infections (such as C. difficile), the selection of resistant pathogens in individual patients, and for the continued development of antimicrobial resistance globally. The growing emergence of multi-drug resistant organisms and the limited development of new agents available to counteract them have caused an impending crisis with alarming implications, especially with regards to Gram-negative bacteria. An international task force from 79 different countries has joined this project by sharing a document on the rational use of antimicrobials for patients with IAIs. The project has been termed AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections). The authors hope that AGORA, involving many of the world's leading experts, can actively raise awareness in health workers and can improve prescribing behavior in treating IAIs.

Large Contaminated Ventral Hernia Repair Using Component Separation Technique with Synthetic Mesh.

BACKGROUND: Large ventral hernia repair represents a major reconstructive surgical challenge, especially under contaminated conditions. Synthetic mesh is usually avoided in these circumstances because of fear of mesh infection, although evidence is outdated and does not regard new materials and techniques. The authors evaluated the safety of synthetic mesh in large contaminated ventral hernia repair. METHODS: All large ventral hernias repaired with the components separation technique and polypropylene mesh were included in analysis. Primary outcomes were wound and medical complications, with a focus on surgical-site infection and mesh removal. For risk analysis, patients were stratified by surgical wound class, Ventral Hernia Working Group grade, and modified Ventral Hernia Working Group grade. RESULTS: One hundred thirty-seven patients were included, with a mean age of 58.6 years, mean body mass index of 26.6 cm2, and mean defect size of 235.6 cm2. Surgical-site infection and total wound complication rates were 16.1 and 48.9 percent, respectively. The surgical wound class distribution of surgical-site infections was as follows: clean, five of 56 (9.1 percent); clean-contaminated, five of 34 (14.7 percent); contaminated, three of 19 (15.8 percent); and dirty/infected, nine of 28 (32.1 percent). Seven meshes (5.1 percent) needed removal, two after clean repairs, three after clean-contaminated repairs, and two after dirty/infected repairs. Surgical wound class (OR, 1.77; 95 percent CI, 1.20 to 2.61) and Ventral Hernia Working Group grade (OR, 2.31; 95 percent CI, 1.24 to 4.28) were predictors of surgical-site infection. CONCLUSION: Rate of surgical-site infection after large contaminated ventral hernia repair with synthetic mesh is considerable but with a low mesh removal rate.

Efficacy and Safety of Ultrapure Alginate-Based Anti-Adhesion Gel in Experimental Peritonitis.

BACKGROUND: Intra-abdominal infection may lead to adhesion and abscess formation. An adhesion barrier can reduce these complications but also aggravate intra-peritoneal infection, causing the opposite effects. The fear of infection propagation has limited clinical adhesion barrier use in a contaminated or infected abdomen. This study evaluated both adhesion and abscess reduction and infection propagation of a new ultrapure alginate-based anti-adhesive barrier gel in a rat peritonitis model. METHODS: In 64 male Wistar rats, bacterial peritonitis was induced via intra-abdominal injection of a mixture of sterile feces, 10(5) colony-forming units (CFU) of Escherichia coli, and 10(4) CFU of Bacteroides fragilis. Surgical debridement and peritoneal lavage were performed 1 h after inoculation. Animals were randomly allocated in equal numbers to a control group or an alginate gel group. Animals were sacrificed on day five post-operatively. Death and the presence and size of intra-abdominal abscesses were noted, and adhesions were scored. All outcomes were compared in the two groups. RESULTS: Seventeen rats (27%) died prematurely without any difference between the groups. Of the surviving rats in the alginate gel group, 88% developed abscesses vs. 100% of the control group. There was no significant difference in the abscess scores or incidence rates of adhesion formation between the groups. The adhesion scores were lower for the alginate gel group compared with control animals (p=0.04). CONCLUSION: Ultrapure alginate gel reduces adhesion severity but not abscesses. The gel seemed to be safe, not aggravating intra-peritoneal infection in this abdominal infection model.

Surgical techniques for parastomal hernia repair: a systematic review of the literature.

BACKGROUND: Parastomal hernias are a frequent complication of enterostomies that require surgical treatment in approximately half of patients. This systematic review aimed to evaluate and compare the safety and effectiveness of the surgical techniques available for parastomal hernia repair. METHODS: Systematic review was performed in accordance with PRISMA. Assessment of methodological quality and selection of studies of parastomal hernia repair was done with a modified MINORS. Subgroups were formed for each surgical technique. Primary outcome was recurrence after at least 1-year follow-up. Secondary outcomes were mortality and postoperative morbidity. Outcomes were analyzed using weighted pooled proportions and logistic regression. RESULTS: Thirty studies were included with the majority retrospective. Suture repair resulted in a significantly increased recurrence rate when compared with mesh repair (odds ratio [OR] 8.9, 95% confidence interval [CI] 5.2-15.1; P < 0.0001). Recurrence rates for mesh repair ranged from 6.9% to 17% and did not differ significantly. In the laparoscopic repair group, the Sugarbaker technique had less recurrences than the keyhole technique (OR 2.3, 95% CI 1.2-4.6; P = 0.016). Morbidity did not differ between techniques. The overall rate of mesh infections was low (3%, 95% CI 2) and comparable for each type of mesh repair. CONCLUSIONS: Suture repair of parastomal hernia should be abandoned because of increased recurrence rates. The use of mesh in parastomal hernia repair significantly reduces recurrence rates and is safe with a low overall rate of mesh infection. In laparoscopic repair, the Sugarbaker technique is superior over the keyhole technique showing fewer recurrences.

SUrgical versus PERcutaneous Bypass: SUPERB-trial; Heparin-bonded endoluminal versus surgical femoro-popliteal bypass: study protocol for a randomized controlled trial.

BACKGROUND: Endovascular treatment options for the superficial femoral artery are evolving rapidly. For long lesions, the venous femoropopliteal bypass considered to be superior above the prosthetic bypass. An endoluminal bypass, however, may provide equal patency rates compared to the prosthetic above knee bypass. The introduction of heparin-bonded endografts may further improve patency rates. The SUrgical versus PERcutaneous Bypass (SuperB) study is designed to assess whether a heparin-bonded endoluminal bypass provides equal patency rates compared to the venous bypass and to prove that it is associated with improved quality of life, related to a decreased complication rate, or not. METHODS/DESIGN: Two-hundred-twenty-two patients with peripheral arterial occlusive disease, category 3-6 according to Rutherford, will be randomized in two treatment arms; 1. the surgical femoro-popliteal bypass, venous whenever possible, and 2. the heparin-bonded endoluminal bypass. The power analysis was based on a non-inferiority principle, with an effect size of 90% and 10% margins (alpha 5%, power 80%). Patients will be recruited from 5 teaching hospitals in the Netherlands during a 2-year period. The primary endpoint is primary patency and quality of life evaluated by the RAND-36 questionnaire and the Walking Impairment Questionnaire. Secondary endpoints include secondary patency, freedom-from-TLR and complications. DISCUSSION: The SuperB trial is a multicentre randomized controlled trial designed to show non-inferiority in patency rates of the heparin-bonded endograft compared to the surgical bypass for treatment of long SFA lesions, and to prove a better quality of life using the heparin bonded-endograft compared to surgically treatment, related to a reduction in complications. TRIAL REGISTRATION: Clinicaltrials: NCT01220245.

Repair of parastomal hernias with biologic grafts: a systematic review.

BACKGROUND: Biologic grafts are increasingly used instead of synthetic mesh for parastomal hernia repair due to concerns of synthetic mesh-related complications. This systematic review was designed to evaluate the use of these collagen-based scaffolds for the repair of parastomal hernias. METHODS: Studies were retrieved after searching the electronic databases MEDLINE, EMBASE and Cochrane CENTRAL. The search terms 'paracolostomy', 'paraileostomy', 'parastomal', 'colostomy', 'ileostomy', 'hernia', 'defect', 'closure', 'repair' and 'reconstruction' were used. Selection of studies and assessment of methodological quality were performed with a modified MINORS index. All reports on repair of parastomal hernias using a collagen-based biologic scaffold to reinforce or bridge the defect were included. Outcomes were recurrence rate, mortality and morbidity. RESULTS: Four retrospective studies with a combined enrolment of 57 patients were included. Recurrence occurred in 15.7% (95% confidence interval [CI] 7.8-25.9) of patients and wound-related complications in 26.2% (95% CI 14.7-39.5). No mortality or graft infections were reported. CONCLUSIONS: The use of reinforcing or bridging biologic grafts during parastomal hernia repair results in acceptable rates of recurrence and complications. However, given the similar rates of recurrence and complications achieved using synthetic mesh in this scenario, the evidence does not support use of biologic grafts.

Patterns of treatment in Australian men following fracture.

UNLABELLED: This study aimed to describe treatment initiation rates for men who had recently sustained a fracture. Most (75.9%) men potentially eligible for subsidised treatment at the time of fracture remained untreated even after a subsequent fracture. INTRODUCTION: This study aimed to describe treatment initiation rates for men who had recently sustained a fracture. METHODS: The study was conducted as part of the Geelong Osteoporosis Study in south-eastern Australia. Men in the study area who had sustained an incident fracture in the period July 2006 to December 2007 were identified from hospital radiology reports. A self-report questionnaire was sent to eligible participants approximately 12 months after fracture. Respondents were asked for details of medications prescribed for 'osteoporosis/fracture/low bone mass' before and after fracture, and where applicable, reasons for cessation of treatment. We analysed the results for 109 men aged 50 years and older who had sustained fracture in the study period. RESULTS: Most (75.9%) men potentially eligible for subsidised treatment at the time of fracture remained untreated. Of the 87 men who were untreated, nine had osteoporosis at the hip and/or spine and 29 (26.6%) reported having sustained a low trauma prior fracture. CONCLUSIONS: Our findings are consistent with previously published data showing low rates of treatment initiation in men eligible for osteoporosis treatment. There appear to be barriers involving participants' and medical practitioners' knowledge, beliefs and attitudes regarding osteoporosis and treatment, as well as in the doctor-patient partnership in osteoporosis management. Establishment of clinical pathways for fracture management beyond orthopaedic care may be one of a range of appropriate responses.

Peritoneal cytokines predict mortality after surgical treatment of secondary peritonitis in the rat.

BACKGROUND: The study aimed to analyze if peritoneal cytokine levels can predict survival in an experimental model for peritonitis. Early identification of patients most at risk for adverse outcomes would facilitate the decision for aggressive therapy in order to maximally exploit their chance for survival. STUDY DESIGN: Peritonitis was induced by intraperitoneal injection of a feces/bacteria mixture in 175 rats. Surgical debridement was performed after 1 hour. Abdominal fluid samples were taken after 24 and 72 hours for the measurement of interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha. Surviving animals were sacrificed after 5 days and correlations between cytokine levels and survival were analyzed. RESULTS: Altogether, 60 animals died prematurely, 12 before the first sampling of cytokines. So, 48 nonsurvivors and 115 survivors were analyzed. Peritoneal cytokine levels were much higher (p < 0.0001) in nonsurvivors than in survivors. At 24 hours there were strong correlations between cytokine levels, especially between IL-6 and IL-10 (r = 0.93). Peritoneal cytokines at 24 hours also discriminated between animals dying within the next 24 hours and those dying later. A strongly (p < 0.0001) increased mortality was observed if IL-6, IL-10, or TNF-alpha levels exceeded 2, 1, or 0.2 ng/mL, respectively. Receiver operating characteristic curves were promising for all 3, but IL-10 showed the best characteristics, with an area under the curve of 0.94 and 67% sensitivity at 95% specificity, obtained at a cut-off value of 1.26 ng/mL. CONCLUSIONS: These data should generate renewed interest to examine the peritoneal cytokines as early markers for adverse outcomes in patients with secondary peritonitis. Possibly, combinations of peritoneal cytokines with other markers can lead to much needed, reliable early prediction of disease severity.

Timing and dose of tissue plasminogen activator to prevent abscess formation after surgical treatment of secondary peritonitis in the rat.

Early administration of fibrinolytics after surgical treatment of peritonitis in the rat reduces abscess formation. The current study investigates the effect of various treatment protocols using intraperitoneal recombinant tissue plasminogen activator (rtPA). Peritonitis was induced in rats and surgical debridement was performed after 1 hour. Animals were treated with rtPA at different time points. Abdominal fluid samples were taken at 24, 72, and 120 hours for cytokine measurements and cell counts. After 5 days the abdomen was inspected for abscesses. Early administration of rtPA significantly reduced the number of rats with abscesses and the abscess load per rat. Delayed treatment significantly reduced abscess load but not the incidence of abscesses. No meaningful differences in the local inflammatory response were found. rtPA was most effective when applied early and continued for 72 hours, although mortality increased after prolonged treatment. rtPA consistently reduces intra-abdominal abscess formation, and a clinical study seems warranted.

Tissue-type plasminogen activator prevents abscess formation but does not affect healing of bowel anastomoses and laparotomy wounds in rats with secondary peritonitis.

BACKGROUND: Intra-abdominal application of recombinant tissue-type plasminogen activator (rtPA) can decrease the rate of abscess formation in a rat peritonitis model. Before using rtPA clinically, its effects on healing of bowel anastomoses and laparotomy wounds should be investigated. METHODS: Peritonitis was induced in 148 male Wistar rats via intra-abdominal injection of a feces/bacteria mixture. Laparotomy, operative debridement and construction of a colo-colostomy after a limited colectomy or ileo-ileostomy after a limited ileal resection were performed after 1 hour. All animals received antibiotics (ceftriaxone plus metronidazole). In addition to untreated controls, other animals received rtPA in 1 of 3 dosing schemes, starting immediately after operation or 24 hour afterwards. Wound strength and hydroxyproline content of the wound were analyzed after 3 or 7 days. RESULTS: Mortality was 2% and manifestations of excessive bleeding were virtually absent. RtPA significantly decreased the rate of abscess formation. Neither bursting pressure nor breaking strength of the anastomoses was affected by any of the rtPA protocols. The same was true for wound strength in the abdominal fascia. Additionally, wound hydroxyproline content and architecture remained unchanged after rtPA administration. CONCLUSION: Intraperitoneal rtPA administration consistently and significantly decreased the rate of abscess formation, but did not affect wound healing. Clinical studies investigating its potential as an adjunct in the treatment of secondary peritonitis may be warranted.

Tissue-type plasminogen activator prevents formation of intra-abdominal abscesses after surgical treatment of secondary peritonitis in a rat model.

BACKGROUND: Optimal therapy of secondary peritonitis frequently results in the formation of residual abscesses, which bear a substantial mortality and morbidity. This study aims to prove that fibrinolytic therapy with recombinant tissue plasminogen activator (rtPA) can reduce abscess formation after surgical treatment of secondary peritonitis in a rat model, without causing unwanted side effects. MATERIALS AND METHODS: Male Wistar rats received an intra-abdominal injection with a suspension of sterile feces, 10(5) cfu Escherichia coli and 10(4) cfu Bacteroides fragilis. Surgical debridement was performed 1 h after inoculation. Animals were randomized into four groups (n = 14 each). Three groups received human rtPA at 1 h (rtPA1); 1 h and 6 h (rtPA2); and 1, 6, and 24 h (rtPA3), respectively. Each dose contained 1.25 mg rtPA. Controls received saline only. Animals were killed after 5 days. RESULTS: rtPA treatment reduced abscess formation in surviving animals, depending on number of doses given. Animals in group rtPA3 had no abscesses in contrast to 88% of the controls (mean 3.6 +/- 2.7 abscesses per rat; p < 0.05). In the rtPA1 and rtPA2 group, frequency of abscess formation was 58 and 33%, respectively. Mortality, course of body weight, and bacteremia were not affected by rtPA and neither were peritoneal cell counts and levels of TNF-alpha, IL-1beta, IL-6 and IL-10. No bleeding complications were observed. CONCLUSION: rtPA reduces intra-abdominal abscess formation after surgical treatment of generalized peritonitis without increasing mortality or affecting the local inflammatory response.

A peritonitis model with low mortality and persisting intra-abdominal abscesses.

Intra-abdominal abscesses are a potential source of recurrent or residual infection after surgical intervention for secondary peritonitis. The development of therapies requires a model which combines low mortality with the formation of persisting abscesses and which is also suitable to study the local inflammatory response. Male Wistar rats were injected intraperitoneally with a mixture of sterile rat faeces, increasing doses of E. coli (10(4)-10(8) cfu/ml) and a fixed dose of B. Fragilis (10(4) cfu/ml). After one h a laparotomy was performed and the peritoneal cavity was debrided. Blood samples were taken under anaesthesia after 6 and 24 h. Abdominal fluid samples were collected (by laparotomy) after 24 and 72 h. The rats were killed after 5 days and the abdomen was inspected for abscesses. Mortality was 90% in the two groups with the highest doses of E. coli and 30% in those with the two lowest doses. In the latter groups all surviving rats but one showed intraabdominal abscesses and bacteremia was encountered frequently, especially after 24 h in the 10(5) cfu E. coli group. The groups receiving 10(4)-10(6) cfu E. coli showed similar plasma IL-6 concentrations after 6 h which were lowered significantly after 24 h. No circulating TNF-alpha was found. Considerable concentrations of TNF-alpha, IL-6, IL-1beta, and IL-10, were found in the peritoneal fluid after 24 h but no differences were observed between the contro groups and those receiving 10(4)-10(6) cfu E. coli. At 72 h cytokine levels were reduced significantly and remained the highest in the animals dosed with 10(6) cfu E. coli. The present model is suitable to study the mechanisms involved in, and prevention of, intra-abdominal abscess formation after surgical treatment of generalized peritonitis.