Smaller nadroparin dose reductions required for patients with renal impairment: A multicenter cohort study.

BACKGROUND: Guidelines advise 50 % and 25 % dose reduction of the therapeutic nadroparin dose (86 IU/kg) in patients with eGFR 15-29 and 30-60 ml/min respectively. For monitoring, peak anti-Xa levels are suggested. Data lack whether this results in therapeutic anti-Xa levels or in anti-Xa levels that are comparable to those of patients without renal impairment. AIMS: To determine dose ranges in patients with renal impairment that result in therapeutic anti-Xa levels and to determine the percentage of the 86 IU/kg dose that results in anti-Xa levels normally occurring in patients without renal impairment. METHODS: A retrospective cohort study was conducted in five hospitals. Patients ≥18 years of age, with an eGFR ≥ 15 ml/min were included. The first correctly sampled peak (i.e. 3-5 h after ≥ third administration, regardless of dose per patient) was included. Simulated prediction models were developed using multiple linear regression. RESULTS: 770 patients were included. eGFR and hospital affected the association between dose and anti-Xa level. The doses for peak anti-Xa levels of 0.75 IU/ml differed substantially between hospitals and ranged from 55 to 91, 65-359 and 68-168 IU/kg in eGFR 15-29, 30-60 and > 60 ml/min/1.73m2, respectively. In eGFR 15-29 and 30-60 ml/min/1.73m2, doses of 75 % and 91 % of 86 IU/kg respectively, were needed for anti-Xa levels normally occurring in patients with eGFR > 60 ml/min. CONCLUSION: We advise against anti-Xa based dose-adjustments as long as anti-Xa assays between laboratories are not harmonized and an anti-Xa target range is not validated. A better approach might be to target levels similar to eGFR > 60 ml/min/1.73m2, which are achieved by smaller dose reductions.

Soft tissue response and determination of underlying risk drivers for recession and mucositis after AMSJI implantation in the maxilla.

PURPOSE: There are few treatment options for oral rehabilitation in patients with advanced maxillary resorption (Cawood-Howell Class V or more). Patient-specific, 3D-printed titanium subperiosteal implants have been described as a potentially valuable alternative solution. Surgeon and patient mediated functional outcomes have been studied and the results are promising. The surrounding soft tissue health has been much less researched. This study aims to evaluate the soft tissue response to the placement of additively manufactured subperiosteal jaw implants (AMSJI®) in the severely atrophic maxilla and to identify possible risk factors for soft tissue breakdown. MATERIALS AND METHODS: An international multicenter study was conducted and fifteen men (mean age 64.62 years, SD ± 6.75) and twenty-five women (mean age 65.24 years, SD ± 6.77) with advanced maxillary jaw resorption (Cawood-Howell Class V or more) were included in this study. General patient data were collected and all subjects were clinically examined. Inclusion criteria were patients who underwent bilateral AMSJI placement® in the maxilla at least a year before and whose surgeon and themselves agreed to participate in the study before their inclusion. RESULTS: A total of forty patients were enrolled with a mean follow-up period of 917 days (SD ± 306.89 days). Primary stability of the implant was achieved postoperatively in all cases, and all implants were loaded with a final prosthesis. At the time of study, only one patient showed mobility of the bilateral AMSJI (more than 1 mm). Exposure of the framework, due to mucosal recession, was seen in 26 patients (65%) and was mainly in the left (21.43%) and right (18.57%) mid-lateral region. Thin biotype and the presence of mucositis were found to be risk factors (p-value < 0.05). Although not significant, smokers had a nearly seven times (Odds ratio 6.88, p=0.08) more risk of developing a recession compared to nonsmokers. CONCLUSION: Twenty-six (65%) patients presented with a recession in one or (more) of the seven regions after oral rehabilitation with bilateral AMSJI installation. Several risk drivers were evaluated. The collapse of soft tissues around the AMSJI that led to caudal exposure of the arms was correlated with a thin biotype and the presence of mucositis.

The use of in-hospital medical care for patients with metastasized colon, bronchus, or lung cancer.

PURPOSE: At the end of life, patients and their families tend to favor adequate pain and symptom management and attention to comfort measures over prolongation of life. However, it has been suggested that many cancer patients without curative options still receive aggressive treatment. We therefore aimed to describe the number of diagnostic procedures, hospitalization, and medication use among these patients as well as factors associated with receiving such care. METHODS: We conducted a cohort study on all patients with metastasized cancer from a primary colon or bronchus and lung (BL) neoplasm from the moment of first admittance (January-December 2017) to end of follow-up (November 2018) or death. RESULTS: A total of 408 patients with colon (36%) or BL (64%) cancer were included in this study, with a median survival time of 7.4 months. 93% of the patients were subjected to at least one diagnostic procedure, 49% received chemotherapy, and 56% received expensive medication including immunotherapy. Patients had a median of 4.6 hospital admissions and 2.3 emergency room (ER) visits. A quarter of all patients (n = 105) received specialized palliative care with a mean of 1.96 consultations and the first consultation after a median time of 4.1 months. Patients with BL neoplasms received significantly more diagnostic procedures, chemotherapy episodes, ER/ICU admissions, and more often received an end-of-life statement per person-year than patients with a primary colon neoplasm. Females received significantly less diagnostic procedures and visited the ER/ICU less frequently than males, and patients aged > 70 years received significantly less chemotherapy (episodes) and expensive medication than younger patients. No differences in care were found between different socioeconomic status groups. CONCLUSION: Patients with metastasized colon or BL cancer receive a large amount of in-hospital medical care. Specialized palliative care was initiated relatively late despite the incurable disease status of all patients. Factors associated with more procedures were BL neoplasms, age between 50 and 70, and male gender.

Deep learning for surgical phase recognition using endoscopic videos.

BACKGROUND: Operating room planning is a complex task as pre-operative estimations of procedure duration have a limited accuracy. This is due to large variations in the course of procedures. Therefore, information about the progress of procedures is essential to adapt the daily operating room schedule accordingly. This information should ideally be objective, automatically retrievable and in real-time. Recordings made during endoscopic surgeries are a potential source of progress information. A trained observer is able to recognize the ongoing surgical phase from watching these videos. The introduction of deep learning techniques brought up opportunities to automatically retrieve information from surgical videos. The aim of this study was to apply state-of-the art deep learning techniques on a new set of endoscopic videos to automatically recognize the progress of a procedure, and to assess the feasibility of the approach in terms of performance, scalability and practical considerations. METHODS: A dataset of 33 laparoscopic cholecystectomies (LC) and 35 total laparoscopic hysterectomies (TLH) was used. The surgical tools that were used and the ongoing surgical phases were annotated in the recordings. Neural networks were trained on a subset of annotated videos. The automatic recognition of surgical tools and phases was then assessed on another subset. The scalability of the networks was tested and practical considerations were kept up. RESULTS: The performance of the surgical tools and phase recognition reached an average precision and recall between 0.77 and 0.89. The scalability tests showed diverging results. Legal considerations had to be taken into account and a considerable amount of time was needed to annotate the datasets. CONCLUSION: This study shows the potential of deep learning to automatically recognize information contained in surgical videos. This study also provides insights in the applicability of such a technique to support operating room planning.

Patients want to be seen: The top 3 information needs of patients with inguinal hernia.

BACKGROUND: Good patient information has shown to improve surgical outcomes. In this study we explore what kind of pre-surgical information patients need and if the provision of a 360˚ video of a surgical procedure can be of added value to the information provided by the hospital. METHODS: An explorative qualitative study using semi-structured interviews on information needs was conducted among 17 inguinal hernia patients to gain more insight in the patients' present surgical information needs. Patients either were planned to receive or already had received a surgical procedure. Questions were asked about the current information provision and, after being shown a 360˚ video of the surgery, whether this would be of added value. RESULTS: Of the total group of 17 patients (mean age 56, interquartile range 45-64) 16 were male and one was female. Most had no previous experience with virtual reality (14/17), already had undergone a surgical procedure (11/17). Patient information needs were all about "seeing" which can be viewed from three different perspectives [1] being seen as a unique person in the treatment process, [2] being seen as a partner, and [3] seeing is understanding. Patients wanted the contact with the doctor to be more personal, with the possibility to see the anesthetist in person, the surgeon to see their wound in the recovery phase, and to receive personal answers to questions about their specific situation. Patients found the 360-video not fearsome, and believed that visual content could be beneficial as it appeals more to their imagination than written or oral information and increases their understanding. It also provided them with a better understanding of their treatment options, their pre-, peri-, and post-surgical procedures and identification of the cause of post-operative side effects. CONCLUSION: To address patients' information needs, complementary tools or services are needed that increase personal contact as well as tailor it to individual patient's needs. Even though video-apps are a partial alternative, hospitals should still offer patients the possibility of having face-to-face meetings with physicians as this is highly valued by patients and leads to increased trust in physicians' performance.

Outcomes of renal replacement therapy in boys with prune belly syndrome: findings from the ESPN/ERA-EDTA Registry.

BACKGROUND: As outcome data for prune belly syndrome (PBS) complicated by end-stage renal disease are scarce, we analyzed characteristics and outcomes of children with PBS using the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) Registry data. METHODS: Data were available for 88 male PBS patients aged <20 years who started renal replacement therapy (RRT) between 1990 and 2013 in 35 European countries. Patient characteristics, survival, and transplantation outcomes were compared with those of male patients requiring RRT due to congenital obstructive uropathy (COU) and renal hypoplasia or dysplasia (RHD). RESULTS: Median age at onset of RRT in PBS was lower [7.0; interquartile range (IQR) 0.9-12.2 years] than in COU (9.6; IQR: 3.0-14.1 years) and RHD (9.4; IQR: 2.7-14.2 years). Unadjusted 10-year patient survival was 85% for PBS, 94% for COU, and 91% for RHD. After adjustment for country, period, and age, PBS mortality was similar to that of RHD but higher compared with COU [hazard ratio (HR) 1.96, 95% confidence interval (CI) 1.03-3.74]. Seventy-four PBS patients (84%) received a first kidney transplant after a median time on dialysis of 8.4 (IQR 0.0-21.1) months. Outcomes with respect to time on dialysis before transplantation, chance of receiving a first transplant within 2 years after commencing RRT, and death-censored, adjusted risk of graft loss were similar for all groups. CONCLUSIONS: This study in the largest cohort of male patients with PBS receiving RRT to date demonstrates that outcomes are comparable with other congenital anomalies of the kidney and urinary tract, except for a slightly higher mortality risk compared with patients with COU.

The difference in endoscopic yield in patients with either iron-deficiency anemia or anemia with normal ferritin.

OBJECTIVE: Current guidelines recommend a gastroduodenoscopy (GDS) and colonoscopy in patients with iron-deficiency anemia (IDA). However, in daily practice, patients with nonferriprive anemia are also referred for endoscopy. The aim of this study is to compare the diagnostic yield of colonoscopy and GDS in patients with IDA and non-IDA. PATIENTS AND METHODS: A retrospective single-center cohort study was carried out from January 2013 till February 2016 that included 917 patients with anemia. We compared the endoscopic yield in patients with IDA versus patients with anemia otherwise. Multivariate regression analyses were carried out to identify predictive factors for the diagnostic yield of GDS and colonoscopy. RESULTS: The yield of both GDS (25%) and colonoscopy (30%) was comparable in IDA and non-IDA patients. However, in patients without known gastrointestinal medical history and without concomitant indications for endoscopy (N=373), the diagnostic yield of GDS was three times higher in IDA patients compared with non-IDA patients (P<0.01). The diagnostic yield for colonoscopy was not significantly different between the two groups. Age and sex were recurrent predictive variables in the outcome of both GDS and colonoscopies. CONCLUSION: We recommend IDA as well as non-IDA as indications for GDS and colonoscopy. Only in patients without gastrointestinal history or localizing complaints a significant difference in the diagnostic yield is found between IDA and non-IDA patients. In this group, upper endoscopy can be omitted in non-IDA patients as they were three times less likely to have a bleeding source found on GDS compared with IDA patients.

Infants Requiring Maintenance Dialysis: Outcomes of Hemodialysis and Peritoneal Dialysis.

BACKGROUND: The impact of different dialysis modalities on clinical outcomes has not been explored in young infants with chronic kidney failure. STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: Data were extracted from the ESPN/ERA-EDTA Registry. This analysis included 1,063 infants 12 months or younger who initiated dialysis therapy in 1991 to 2013. FACTOR: Type of dialysis modality. OUTCOMES & MEASUREMENTS: Differences between infants treated with peritoneal dialysis (PD) or hemodialysis (HD) in patient survival, technique survival, and access to kidney transplantation were examined using Cox regression analysis while adjusting for age at dialysis therapy initiation, sex, underlying kidney disease, and country of residence. RESULTS: 917 infants initiated dialysis therapy on PD, and 146, on HD. Median age at dialysis therapy initiation was 4.5 (IQR, 0.7-7.9) months, and median body weight was 5.7 (IQR, 3.7-7.5) kg. Although the groups were homogeneous regarding age and sex, infants treated with PD more often had congenital anomalies of the kidney and urinary tract (CAKUT; 48% vs 27%), whereas those on HD therapy more frequently had metabolic disorders (12% vs 4%). Risk factors for death were younger age at dialysis therapy initiation (HR per each 1-month later initiation, 0.95; 95% CI, 0.90-0.97) and non-CAKUT cause of chronic kidney failure (HR, 1.49; 95% CI, 1.08-2.04). Mortality risk and likelihood of transplantation were equal in PD and HD patients, whereas HD patients had a higher risk for changing dialysis treatment (adjusted HR, 1.64; 95% CI, 1.17-2.31). LIMITATIONS: Inability to control for unmeasured confounders not included in the Registry database and missing data (ie, comorbid conditions). Low statistical power because of relatively small number of participants. CONCLUSIONS: Despite a widespread preconception that HD should be reserved for cases in which PD is not feasible, in Europe, we found 1 in 8 infants in need of maintenance dialysis to be initiated on HD therapy. Patient characteristics at dialysis therapy initiation, prospective survival, and time to transplantation were very similar for infants initiated on PD or HD therapy.

Mortality from infections and malignancies in patients treated with renal replacement therapy: data from the ERA-EDTA registry.

BACKGROUND: Infections and malignancies are the most common non-cardiovascular causes of death in patients on chronic renal replacement therapy (RRT). Here, we aimed to quantify the mortality risk attributed to infections and malignancies in dialysis patients and kidney transplant recipients when compared with the general population by age group and sex. METHODS: We followed 168 156 patients included in the ERA-EDTA registry who started RRT in 1993-2007 until 1 January 2012. Age- and cause-specific mortality rates per 1000 person-years (py) and mortality rate ratios (MRRs) compared with the European general population (WHO) were calculated. To identify risk factors, we used Cox regression. RESULTS: Infection-related mortality was increased 82-fold in dialysis patients and 32-fold in transplant recipients compared with the general population. Female sex, diabetes, cancer and multisystem disease were associated with an increased risk of infection-related mortality. The sex difference was most pronounced for dialysis patients aged 0-39 years, with women having a 32% (adjusted HR 1.32 95% CI 1.09-1.60) higher risk of infection-related mortality than men. Mortality from malignancies was 2.9 times higher in dialysis patients and 1.7 times higher in transplant recipients than in the general population. Cancer and multisystem disease as primary causes of end-stage renal disease were associated with higher mortality from malignancies. CONCLUSION: Infection-related mortality is highly increased in dialysis and kidney transplant patients, while the risk of malignancy-related death is moderately increased. Young women on dialysis may deserve special attention because of their high excess risk of infection-related mortality. Further research into the mechanisms, prevention and optimal treatment of infections in this vulnerable population is required.

Renal replacement therapy for rare diseases affecting the kidney: an analysis of the ERA-EDTA Registry.

BACKGROUND: In recent years, increased efforts have been undertaken to address the needs of patients with rare diseases by international initiatives and consortia devoted to rare disease research and management. However, information on the overall prevalence of rare diseases within the end-stage renal disease (ESRD) population is limited. The aims of this study were (i) to identify those rare diseases within the ERA-EDTA Registry for which renal replacement therapy (RRT) is being provided and (ii) to determine the prevalence and incidence of RRT for ESRD due to rare diseases, both overall and separately for children and adults. METHODS: The Orphanet classification of rare disease was searched for rare diseases potentially causing ESRD, and these diagnosis codes were mapped to the corresponding ERA-EDTA primary renal disease codes. Thirty-one diagnoses were defined as rare diseases causing ESRD. RESULTS: From 1 January 2007 to 31 December 2011, 7194 patients started RRT for a rare disease (10.6% children). While some diseases were exclusively found in adults (e.g. Fabry disease), primary oxalosis, cystinosis, congenital anomalies of the kidney and urinary tract (CAKUT) and medullary cystic kidney disease affected young patients in up to 46%. On 31 December 2011, 20 595 patients (12.4% of the total RRT population) were on RRT for ESRD caused by a rare disease. The point prevalence was 32.5 per million age-related population in children and 152.0 in adults. Only 5.8% of these patients were younger than 20 years; however, 57.7% of all children on RRT had a rare disease, compared with only 11.9% in adults. CAKUT and focal segmental glomerulosclerosis were the most prevalent rare disease entities among patients on RRT. CONCLUSIONS: More than half of all children and one of nine adults on RRT in the ERA-EDTA Registry suffer from kidney failure due to a rare disease, potentially with a large number of additional undiagnosed or miscoded cases. Comprehensive diagnostic assessment and the application of accurate disease classification systems are essential for improving the identification and management of patients with rare kidney diseases.

Impact of graft loss among kidney diseases with a high risk of post-transplant recurrence in the paediatric population.

BACKGROUND: Some kidney diseases tend to recur in the renal allograft after transplantation. We studied the risk of graft loss among primary renal diseases known for their high risk of recurrence and compared it with that of patients with hypoplasia and/or dysplasia. METHODS: Within the European Society of Paediatric Nephrology and European Renal Association and European Dialysis and Transplant Association (ESPN/ERA-EDTA) registry, we studied children from 33 countries who received a kidney transplant before the age of 20 between 1990 and 2009. Patients were censored after 5 years of follow-up and cumulative incidence competing risk analysis was used to calculate survival curves. RESULTS: Patients with focal and segmental glomerulosclerosis (FSGS), haemolytic uraemic syndrome (HUS), membranoproliferative glomerulonephritis Type I or II (MPGN), IgA nephropathy or Henoch Schönlein Purpura (HSP/IgA) or systemic lupus erythomatosus (SLE) underwent pre-emptive transplantation significantly less often than patients with hypoplasia and/or dysplasia. The rate of living donation was lower among patients with FSGS and SLE than in patients with hypoplasia and/or dysplasia. In comparison with hypoplasia and/or dysplasia patients with a risk of 14.4%, the 5-year risk of graft loss was significantly increased in patients with FSGS (25.7%) and MPGN (32.4%) while it was not significantly increased in children with HUS (18.9%), HSP/IgA (16.3%) or SLE (20.3%). One-year graft survival strongly improved among HUS patients from 17.1% in 1995-1999 to 3.6% in 2005-2009 and was not accompanied by a decrease in the number of transplantations. CONCLUSION: The risk of graft loss is increased among specific causes of renal failure with a high risk of post-transplant recurrence. It seems likely that, due to anticipation of such risk, physicians perform less pre-emptive transplantation and provide fewer grafts from living related donors in patients with these conditions. Improved risk stratification by physicians, resulting in the identification of patients with HUS at higher or lower risk of recurrence, might explain the much improved graft survival rates.

Timing and outcome of renal replacement therapy in patients with congenital malformations of the kidney and urinary tract.

BACKGROUND AND OBJECTIVES: Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of ESRD in children, but the proportion of patients with individual CAKUT entities progressing to ESRD during adulthood and their long-term clinical outcomes are unknown. This study assessed the age at onset of renal replacement therapy (RRT) and patient and renal graft survival in patients with CAKUT across the entire age range. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Patients with CAKUT were compared with age-matched patients who were undergoing RRT for other renal disorders on the basis of data from the European Renal Association-European Dialysis and Transplant Association Registry. Competing risk and Cox regression analyses were conducted. RESULTS: Of 212,930 patients commencing RRT from 1990 to 2009, 4765 (2.2%) had renal diagnoses consistent with CAKUT. The proportion of incident RRT patients with CAKUT decreased from infancy to childhood and then increased until age 15-19 years, followed by a gradual decline throughout adulthood. Median age at RRT start was 31 years in the CAKUT cohort and 61 years in the non-CAKUT cohort (P<0.001). RRT was started earlier (median, 16 years) in patients with isolated renal dysplasia than in those with renal hypoplasia and associated urinary tract disorders (median, 29.5-39.5 years). Patients with CAKUT survived longer than age- and sex-matched non-CAKUT controls because of lower cardiovascular mortality (10-year survival rate, 76.4% versus 70.7%; P<0.001). CONCLUSIONS: CAKUT leads to ESRD more often at adult than pediatric age. Treatment outcomes differ from those of acquired kidney diseases and vary within CAKUT subcategories.

Prevalence and predictors of the sub-target Hb level in children on dialysis.

BACKGROUND: Anaemia is a common and potentially treatable co-morbidity of end-stage renal disease. We aimed to determine the prevalence of the sub-target haemoglobin (Hb) level among European children on dialysis and to identify factors associated with a low Hb level. METHODS: From the European Society for Paediatric Nephrology (ESPN)/European Renal Association-European Dialysis Transplant Association (ERA-EDTA) registry, data were available on 2351 children between 1 month and 18 years of age, totalling 5546 measurements from 19 countries. RESULTS: The mean Hb level was 10.8 g/dL (5th-95th percentiles, 7.4-13.9). Among those above 2 years of age, the mean Hb level was 10.9 g/dL (11.4% below 8.5 g/dL), while it was 10.3 g/dL among those below 2 years (11.2% below 8.0 g/dL). A total of 91.2% of the patients were on an erythropoiesis-stimulating agent (ESA). Hb levels increased with age and were higher in peritoneal dialysis compared with haemodialysis patients. Patients with congenital anomalies of the kidney and urinary tract showed the highest Hb levels, and those with cystic kidney diseases or metabolic disorders the lowest ones. Ferritin levels between 25 and 50 ng/mL were associated with the highest Hb levels. We found a weak inverse association between parathyroid hormone (PTH) and Hb. Whereas standardized blood pressure (BP) was not elevated in patients with above-target Hb, elevated systolic BP z-score was noted in those with sub-target Hb levels. CONCLUSIONS: Sub-target Hb levels remain common in children on dialysis, in spite of virtually all children being treated with ESA; although we cannot exclude under-dosing. Optimal ferritin levels seemed to be slightly lower in children (25-50 ng/mL) than those in adults. Other risk factors for sub-target Hb are dialysis modality and a high PTH level.

Improvement in the renal prognosis in nephropathic cystinosis.

BACKGROUND AND OBJECTIVES: Nephropathic cystinosis (NC) is an autosomal recessive disorder occurring in one to two per 100,000 newborns. Because of the rarity of NC, long-term outcome data are scarce. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: 245 NC patients from 18 countries provided data to the ESPN/ERA-EDTA registry. We matched NC patients on renal replacement therapy (RRT) to non-NC children on RRT. RESULTS: Between 1979 and 2008, mean age at the start of RRT among NC children increased by 0.15 year per calendar year (95% confidence interval, 0.10 to 0.21) from 8.8 to 12.7 years, whereas we did not observe this in non-NC children. Five-year survival after the start of RRT improved in NC patients from 86.1% (before 1990) to 100% (since 2000) as compared with the control population (89.6% and 94.0%). NC patients received a renal allograft more often (relative risk, 1.09; 95% confidence interval, 1.00 to 1.17) as compared with matched RRT children, and 5-year graft survival was better (94.0% versus 84.0%). NC dialysis patients were less often hypertensive than non-NC children matched for age, country, and dialysis modality (42.7% versus 51.7%) and had lower parathyroid hormone levels (median, 56 versus 140 pg/ml). Although height at start of RRT slightly improved during the past decade, children with NC remained significantly shorter than non-NC children at the start of RRT. CONCLUSIONS: We demonstrated improved survival of the renal function as well as better patient and graft survival after the start of RRT in a large European cohort of NC patients over the last two decades.

Minor injuries as a risk factor for venous thrombosis.

BACKGROUND: Injuries increase the risk of venous thrombosis. So far, most research has focused on major injuries that are accompanied by other risk factors for venous thrombosis, such as plaster casts and surgery. We studied the association of venous thrombosis with common minor injuries, such as minor sural muscle ruptures and ankle sprains. METHODS: We performed a large, population-based, case-control study (the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis [MEGA] study), including consecutive patients with a first deep venous thrombosis of the leg or pulmonary embolism and control subjects. Participants with malignant neoplasms, those who underwent surgery, and those who had a plaster cast or extended bed rest were excluded. RESULTS: Of 2471 patients, 289 (11.7%), and of 3534 controls, 154 (4.4%) had a minor injury in the 3 months preceding the venous thrombosis (patients) or completion of the questionnaire (controls). Venous thrombosis was associated with previous minor injury (odds ratio adjusted for sex and age, 3.1; 95% confidence interval, 2.5-3.8). The association was strongest for injuries that occurred in the 4 weeks before thrombosis and was not apparent before 10 weeks. Thrombosis was more strongly associated with minor injuries located in the leg (odds ratio adjusted for sex and age, 5.1; 95% confidence interval, 3.9-6.7), while those located in other body parts were not associated. A 50-fold increased risk was found in factor V Leiden carriers with a leg injury compared with noncarriers without injury (odds ratio, 49.7; 95% confidence interval, 6.8-362.7). CONCLUSIONS: Minor injuries in the leg are associated with greater risk of venous thrombosis. Because minor injuries are common, they could be major contributors to the occurrence of venous thrombosis.