Risk factors for morbidity after appendectomy.

INTRODUCTION: The aim of the present study was to evaluate the risk factors for postoperative complications after an appendectomy with special regard to both the time period from hospital admission to operation and night time surgery. PATIENTS AND METHODS: Patients who underwent an appendectomy due to acute appendicitis and were admitted to the University Hospital Aachen between January 2003 and January 2014 were included in this retrospective analysis. Regarding the occurrence of postoperative complications, patients were divided into the following two groups: the group with complications (group 1) and the group without complications (group 2). RESULTS: Of the 2136 patients who were included in this study, 165 patients (group 1) exhibited complications, and in 1971 patients (group 2), no complications appeared. After a univariate logistic regression analysis, six predictors for postoperative complications were found and are described as follows: (1) complicated appendicitis (odds ratio (OR) 4.8 (3.46-6.66), p < 0.001), (2) operation at night (OR 1.62 (1.17-2.24), p = 0.004), (3) conversion from laparoscopic to open access (OR 37.08 (12.95-106.17), p < 0.001), (4) an age > 70 years (OR 6.00 (3.64-9.89), p < 0.001), (5) elevated CRP (OR 1.01 (1.01-1.01), p < 0.001) and (6) increased WBC count (OR 1.04 (1.01-1.07), p = 0.003). After multivariate logistic regression analysis, a significant association was demonstrated for complicated appendicitis (1.88 (1.06-3.32), p < 0.031), conversion to open access (OR 16.33 (4.52-58.98), p < 0.001), elevated CRP (OR 1.00 (1.00-1.01), p = 0.017) and an age > 70 years (OR 3.91 (2.12-7.21), p < 0.001). The time interval between hospital admission and operation was not associated with postoperative complications in the univariate and multivariate logistic regression analyses, respectively. However, the interaction between complicated appendicitis and the time interval to operation was significant (OR 1.024 (1.00-1.05), p = 0.028). CONCLUSION: Based on our findings, surgical delay in the case of appendicitis and operation at night did not increase the risk for postoperative complications. However, the mean waiting time was less than 12 h and patients aged 70 years or older were at a higher risk for postoperative complications. Furthermore, for the subgroup of patients with complicated appendicitis, the time interval to surgery had a significant influence on the occurrence of postoperative complications. Therefore, the contemporary operation depending on the clinical symptoms and patient age remains our recommendation.

Compositional MRI techniques for evaluation of cartilage degeneration in osteoarthritis.

Osteoarthritis (OA), a leading cause of disability, affects 27 million people in the United States and its prevalence is rising along with the rise in obesity. So far, biomechanical or behavioral interventions as well as attempts to develop disease-modifying OA drugs have been unsuccessful. This may be partly due to antiquated imaging outcome measures such as radiography, which are still endorsed by regulatory agencies such as the United States Food and Drug Administration (FDA) for use in clinical trials. Morphological magnetic resonance imaging (MRI) allows unparalleled multi-feature assessment of the OA joint. Furthermore, advanced MRI techniques also enable evaluation of the biochemical or ultrastructural composition of articular cartilage relevant to OA research. These compositional MRI techniques have the potential to supplement clinical MRI sequences in identifying cartilage degeneration at an earlier stage than is possible today using morphologic sequences only. The purpose of this narrative review is to describe compositional MRI techniques for cartilage evaluation, which include T2 mapping, T2* Mapping, T1 rho, dGEMRIC, gagCEST, sodium imaging and diffusion weighted imaging (DWI). We also reviewed relevant clinical studies that have utilized these techniques for the study of OA. The different techniques are complementary. Some focus on isotropy or the collagen network (e.g., T2 mapping) and others are more specific in regard to tissue composition, e.g., gagCEST or dGEMRIC that convey information on the GAG concentration. The application and feasibility of these techniques is also discussed, as they will play an important role in implementation in larger clinical trials and eventually clinical practice.

Association of cartilage degeneration with four year weight gain--3T MRI data from the Osteoarthritis Initiative.

OBJECTIVE: To determine the effect of weight gain on progression of early knee morphologic abnormalities using magnetic resonance imaging (MRI) in a longitudinal study over 48 months. DESIGN: We studied the right knee of 100 subjects from the Osteoarthritis Initiative (OAI), selecting subjects aged ≥ 45 with osteoarthritis (OA) risk factors who demonstrated weight gain (minimum 5% increase in body mass index, BMI, n = 50) or no change in weight (BMI change < 2%, n = 50), frequency matched for age, gender, and baseline BMI. Baseline and 48 month knee MRI studies were scored for lesions using a modified whole organ MRI score (WORMS). Logistic regression models were used to compare the differences between the two groups. RESULTS: The odds of worsening maximum cartilage (11.3, 95%, CI 3.5-51.4) and meniscal WORMS (4.5, 95% CI 1.4-17.3) were significantly greater in the weight gain group compared to the no change group, in addition to the odds of worsening cartilage defects at the patella and average meniscal WORMS (P < 0.05). Odds of worsening average bone marrow edema pattern (BMEP) were significantly greater for the weight gain group compared to the no change cohort (P < 0.05). CONCLUSION: Our study demonstrated that weight gain is strongly associated with increased progression of cartilage degeneration in middle-aged individuals with risk factors for OA.

Major Esophageal Dilation After Laparoscopic Adjustable Gastric Banding in Symptomatic Patients: Does It Prevent Effective Weight Loss and How Should It be Treated?

INTRODUCTION: Esophageal dilation (ED) has been described as a long-term complication following laparoscopic adjustable gastric banding (LAGB) with an incidence of 0.5-50%. The purpose of this study was to evaluate the effect of major ED on weight loss and find methods to diagnose ED and possible treatment strategies based on a classification. MATERIALS AND METHODS: We performed a retrospective analysis of all patients undergoing LAGB between 2004 and 2008 in three community-based hospitals. ED was classified in four stages of dilation using gastrografin swallow. We report body mass index (BMI), failure rates and reoperations among these patients, with a mean follow-up period of 6.7 years. RESULTS: Nineteen (18.4%) of 103 patients who underwent LAGB presented with esophageal dilation. Band deflation failed for all nine patients (8.7%) with major ED. The mean BMI at LAGB (BMI 1), revision (BMI 2), and 1 year after conversion (BMI 3) were 45.9±3.2, 42.8±4.9 and 30.3±5.5 kg/m2, respectively. No significant difference was found comparing BMI 1 and BMI 2 (p=0,065, EWL1: 14.2±21.7 kg/m2). In contrast, the weight loss after the revision surgery was significant (p=0.001, EWL2: 67.1±30 kg/m2). No significant difference was found concerning age, gender, ASA, preoperative (LAGB) weight, and mean interval between LAGB and revision comparing patients with major ED (IV) to patients with milder forms (ED I-III). CONCLUSION: ED is a serious long-term complication after LAGB and seems to prevent effective weight loss in stage IV. Furthermore, untreated dilation could cause long-term damage to the esophagus. Therefore, we suggest routine radiographic follow-up after LAGB even in asymptomatic patients and a treatment based on a classification with an early surgical revision for major ED.

Physical activity in relation to knee cartilage T2 progression measured with 3 T MRI over a period of 4 years: data from the Osteoarthritis Initiative.

OBJECTIVE: The purpose of this study was to analyze the longitudinal association between physical activity levels and early degenerative cartilage changes in the knee, measured using T2 relaxation times over a period of 4 years in individuals without clinical or radiographic evidence of OA. DESIGN: Cartilage T2 was measured at baseline and after 2 and 4 years in 205 subjects aged 45-60 years from the Osteoarthritis Initiative (OAI) incidence and normal cohorts with no knee pain (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score of zero), and a Kellgren Lawrence (KL) score of <2 at baseline. Physical activity was scored using the Physical Activity Scale for the Elderly (PASE) questionnaire, which was obtained yearly over 4 years. The relationship between physical activity and T2 was studied using a mixed model linear regression, including random effects, and adjusted for age, sex, and body mass index (BMI). RESULTS: T2 values for all PASE tertiles progressed over the 4-year period. T2 progression was increased in the highest tertile of physical activity compared to the mid-tertile at the medial tibia (MT) (P = 0.041), patella (Pat) (P = 0.019), and average T2 of all knee compartments combined (P = 0.033). Subjects with the lowest 15% PASE scores showed significantly higher T2 progression compared to the mid-level physical activity group at the lateral femur (LF) (P = 0.025), lateral tibia (LT) (P = 0.043), medial femur (MF) (P = 0.044), tibiofemoral compartment (P = 0.017), patellofemoral compartment (P = 0.016), lateral compartments (P = 0.003), and average of all compartments (P = 0.043). CONCLUSION: High and very low PASE scores were associated with greater progression of cartilage T2 measurements in asymptomatic, middle-aged individuals, suggesting accelerated cartilage matrix biochemical degeneration over time.

Baseline mean and heterogeneity of MR cartilage T2 are associated with morphologic degeneration of cartilage, meniscus, and bone marrow over 3 years--data from the Osteoarthritis Initiative.

OBJECTIVE: The purpose of this study is to determine whether the mean and heterogeneity of magnetic resonance (MR) knee cartilage T(2) relaxation time measurements at baseline are associated with morphologic degeneration of cartilage, meniscus, and bone marrow tissues over 3 years in subjects with risk factors for osteoarthritis (OA). DESIGN: Subjects with risk factors for OA (n=289) with an age range of 45-55 years were selected from the Osteoarthritis Initiative (OAI) database. 3.0 Tesla MR images were analyzed using morphological gradings of cartilage, bone marrow and menisci whole-organ magnetic resonance imaging scores (WORMS scoring). A T(2) mapping sequence was used to assess the mean and heterogeneity of cartilage T(2) (gray level co-occurrence matrix texture analysis). Regression models were used to assess the relationship between baseline T(2) parameters and changes in morphologic knee WORMS scores over 3 years. RESULTS: The prevalence of knee abnormalities in the cartilage (P<0.0005), meniscus (P<0.00001), and bone marrow significantly (P<0.00001) increased from baseline to 3 years in all compartments combined. The baseline mean and heterogeneity of cartilage T(2) were significantly (P<0.05) associated with morphologic joint degeneration in the cartilage, meniscus and bone marrow over 3 years. CONCLUSIONS: The prevalence of knee abnormalities significantly increased over 3 years; increased cartilage T(2) at baseline predicted longitudinal morphologic degeneration in the cartilage, meniscus, and bone marrow over 3 years in subjects with risk factors for OA.

Association of Physical Activity Measured by Accelerometer, Knee Joint Abnormalities, and Cartilage T2 Measurements Obtained From 3T Magnetic Resonance Imaging: Data From the Osteoarthritis Initiative.

OBJECTIVE: To study the cross-sectional association between physical activity measured with an accelerometer, structural knee abnormalities, and cartilage T2 values assessed with 3T magnetic resonance imaging (MRI). METHODS: We included 274 subjects from the Osteoarthritis Initiative cohort without definite radiographic osteoarthritis (Kellgren/Lawrence grades 0 and 1) and with at most mild pain, stiffness, and functional limitation in the study knee (Western Ontario and McMaster Universities Osteoarthritis Index scale 0-1), which had not limited their activity due to knee pain. Physical activity was measured over 7 days with an ActiGraph GT1M accelerometer. Subjects were categorized by quartile of physical activity based on the average daily minutes of moderate to vigorous physical activity (mv-PA). MRI images of the right knee (at 48-month visit) were assessed for structural abnormalities using a modified Whole-Organ Magnetic Resonance Imaging Score (WORMS) and for T2 relaxation times derived from segmented cartilage of 4 femorotibial regions and the patella. WORMS grades and T2 measurements were compared between activity quartiles using a linear regression model. Covariates included age, sex, body mass index, knee injury, family history of knee replacement, knee symptoms, hip and ankle pain, and daily wear time of the accelerometer. RESULTS: Higher mv-PA was associated with increased severity (P = 0.0087) and number of lesions of the medial meniscus (P = 0.0089) and with severity of bone marrow edema lesions (P = 0.0053). No association between cartilage lesions and mv-PA was found. T2 values of cartilage (loss, damage, and abnormalities) tended to be greater in the higher quartiles of mv-PA, but the differences were nonsignificant. CONCLUSION: In knees without radiographic osteoarthritis in subjects with no or mild knee pain, higher physical activity levels were associated with increases in meniscal and bone marrow edema pattern lesions.

Colonic wall changes in patients with diverticular disease - is there a predisposition for a complicated course?

BACKGROUND: The aim of this study was to evaluate colonic wall changes and enteric neuropathy in patients with either uncomplicated (UDD) or complicated diverticular disease (CDD). Furthermore, we evaluated the presence of an anatomic sphincter at the rectosigmoid junction (RSJ). METHODS: Samples of colonic tissue from fifteen patients with UDD, fifteen patients with CDD and fifteen patients as control were collected. Collagen quotient I/III was measured with the Sirius-red test, expression of MMP-1, MMP-13, innervation (S100), proliferation (Ki67) and apoptosis (TUNEL) in the colonic wall were investigated by immunohistochemical studies. Furthermore, measurements of the different layers were performed to investigate the RSJ. RESULTS: Patients with either UDD or CDD had lower collagen I/III quotients compared to the control group, significant for CDD (p = 0.007). For MMP-1 and MMP-13 only a slight increase for patients with CDD was found. The percentage of proliferating (Ki67) and apoptotic (TUNEL) cells was significantly higher for patients with CDD than in the control group (p = 0.016; p = 0.037). Upon investigating the S100-expression a significant reduce in glial cells density was found in the myenteric and mucosal plexus for both groups (UDD and CDD) compared to the control group. Measurements of the different colon layers oral, aboral and at the RSJ revealed equal values. CONCLUSIONS: This study has shown that colonic wall changes and enteric neuropathy seem to play a role in the pathogenesis of colonic diverticulosis. None of our results suggest a predisposition for a complicated diverticular disease. Furthermore, the presence of an anatomic sphincter at the rectosigmoid junction could not be detected.

Influence of skin closure technique on surgical site infection after loop ileostomy reversal: retrospective cohort study.

BACKGROUND: Intestinal stoma closure is associated with high risk of surgical site infection (SSI) at stoma reversal site. The aim of this retrospective cohort study was to determine the outcome of purse string approximation (PSA) compared to primary linear closure (PLC) of the skin after loop ileostomy reversal. METHODS: Data of 140 patients operated between 2005 and 2012 were analyzed in this two-center-study to determine the outcome of patients with either PSA (n = 44) or PLC (n = 96) after loop ileostomy reversal. RESULTS: Patients in the PSA group were significantly older than in the PLC group (64 ± 15 vs. 57 ± 18; p = 0.026). Cardiac diseases were significantly more present in the PSA group in comparison to the PLC group (59% vs. 38%; p = 0.017). Stoma creation was significantly more often due to malignancy in the PSA group in comparison to the PLC group (68% vs. 50%; p = 0.044). SSI occurred significantly more often in the PLC group in comparison to the PSA group (17% vs. 5%; p = 0.047). CONCLUSIONS: The risk for SSI is lower in patients with PSA in comparison to patients with PLC. In order to diminish SSI we recommend performing a PSA in patients with loop ileostomy reversal.

Association of metabolic risk factors with cartilage degradation assessed by T2 relaxation time at the knee: data from the osteoarthritis initiative.

OBJECTIVE: To evaluate the association of metabolic risk factors with severity and 2-year progression of early degenerative cartilage changes at the knee, measured with T2 relaxation times in middle-aged subjects from the Osteoarthritis Initiative. METHODS: Cartilage segmentation and T2 map generation were performed in knee 3T magnetic resonance images from 403 subjects ages 45-60 years without radiographic osteoarthritis (OA). The influence of risk factors on baseline T2 and longitudinal progression of T2 was analyzed using linear regression, adjusting for age, sex, and other OA risk factors. RESULTS: Four metabolic risk factors, i.e., high abdominal circumference (P < 0.001), hypertension (P = 0.041), high fat consumption (P = 0.023), and self-reported diabetes mellitus (P = 0.010), were individually associated with higher baseline T2. When the 4 metabolic risk factors were considered in a multivariate regression model, higher T2 remained significantly associated with abdominal circumference (P < 0.001) and diabetes mellitus (P = 0.026), and there was a trend for high fat consumption (P = 0.096). For the individual risk factors, only diabetes mellitus remained associated with higher baseline T2 after adjustment for body mass index (BMI). After adjustment for BMI, baseline T2 increased in a dose-response manner with the number of metabolic risk factors present (P = 0.032 for linear trend), and subjects with ≥3 metabolic factors (versus <3) had significantly higher baseline T2 (mean difference 1.2 msec [95% confidence interval 0.3, 2.1]; P = 0.011). Metabolic risk factors were not significantly associated with increases in T2 during followup. CONCLUSION: Metabolic risk factors are associated with higher T2, suggesting that increased cartilage degeneration may be caused by modifiable metabolic disorders.

In vitro and in vivo characteristics of gentamicin-supplemented polyvinylidenfluoride mesh materials.

To reduce infection rates after mesh implantation antibiotic-coated meshes were designed. The aim of the study was to analyze biocompatibility and in vitro efficiency of a modified gentamicin-supplemented polyvinylidenfluoride mesh. Twenty rats were randomized to two groups (PVDF group and Genta group). Mesh material was implanted subcutaneously. Blood samples were taken to determine the gentamicin serum concentration. Seven and 90 days after mesh implantation, animals were euthanized. The inflammatory tissue response was characterized by analyzing the foreign body granuloma. Cellular immune response was analyzed by immunohistochemical investigations. The collagen type I/III ratio was estimated by crosspolarization microscopy. In vitro agar diffusion test, suspension test, and gentamicin release were characterized. Agar diffusion and suspension test showed efficient antibiotic effects of the mesh in vitro. Serum concentrations of gentamicin showed a peak value 1 h postoperatively with a decline within the next day. The total size of the granuloma was significantly smaller in the Genta group compared to the PVDF group at both points of time. Except of a short period of increased expression of CD68 in the Genta group after 7 days, no further difference was found analyzing cellular immune response. The collagen type I/III ratio was widely constant analyzing the two mesh types without significant differences comparing both mesh materials. A significantly decreased foreign body granuloma formation compared to the pure PVDF mesh group was found. In vitro analysis showed efficient antibiotic effects of the Gentamicin supplementation compared to the pure PVDF mesh.

Comparison of long-term biocompability of PVDF and PP meshes.

BACKGROUND: Abdominal hernia repair is the most frequently performed operation in surgery. Mesh repair in hernia surgery has become an integral component. Although meshes made of PVDF are already in clinical use, so far no data of long-term biocompability are available. METHODS: In this study a PVDF mesh was compared to a polypropylene mesh with regard to its long-term biocompatibility. A total of 28 rats were randomized to two groups. Mesh material was implanted subcutaneously; animals were euthanized seven days and six months postoperatively. The quantity of inflammatory tissue response was characterized by measuring the diameter of the foreign body granuloma. Furthermore quality of cellular immune response (T-lymphocytes, macrophages, and neutrophils), and inflammation (COX-2) was analyzed by immunohistochemistry. Furthermore the collagen type I/III ratio was determined. RESULTS: Macrophages, T-lymphocytes, neutrophiles, and COX-2 declined significantly up to six months postoperatively in comparison to day 7 for both PVDF and PP meshes, and in both groups the collagen ratio increased significantly in the course of time. PVDF meshes showed a foreign body granuloma size significantly reduced compared to PP (7 days: 20 ± 2 µm vs. 27 ± 2 µm; 6 months 15 ± 2 µm vs. 22 ± 3 µm; p < .001). However no significant differences were found analyzing cellular response six months postoperatively. CONCLUSIONS: Our current data suggest that even in the long-term course after six months and despite a higher effective surface of the PVDF samples it showed a smaller foreign body granuloma than with PP whereas the cellular response was similar.