Modification of bentonite with black cotton soil and carboxyl methyl cellulose for the enhancement of hydraulic performance of geosynthetic clay liners.

Geosynthetic clay liners (GCLs) are mostly used as flow barriers in landfills and waste containments due to their low hydraulic conductivity to prevent the leachate from reaching the environment. The self-healing and swell-shrink properties of soft clays (expansive soils) such as bentonite enable them as promising materials for the GCL core layers. However, it is important to modify their physico-chemical properties in order to overcome the functional limitations of GCL under different hydraulic conditions. In the present study, locally available black cotton soil (BCS) is introduced in the presence of an anionic polymer named carboxymethyl cellulose (CMC) as an alternative to bentonite to enhance the hydraulic properties of GCL under different compositions. The modified GCL is prepared by stitching the liner with an optimum percentage of CMC along with various percentages of BCS mixed with bentonite. Hydraulic conductivity tests were performed on the modified GCL using the flexi-wall permeameter. The results suggest that the lowest hydraulic conductivity of 4.58 × 10-10 m/s is obtained when 25% of BCS is blended with bentonite and an optimum 8% CMC and further addition of BCS results in the reduction of the hydraulic conductivity.

Whole-exome sequencing identifies two novel ALMS1 mutations in Indian patients with Leber congenital amaurosis.

Leber congenital amaurosis (LCA) is a severe autosomal recessive retinal degenerative disease. The current study describes exome sequencing results for two unrelated Indian LCA patients carrying novel nonsense p.(Glu636*) and frameshift p.(Pro2281Leufs*63) mutations in the ALMS1 gene. Although ALMS1 gene mutations are associated with Alstrom syndrome (AS), the current patients did not exhibit typical syndromic features of AS. These data suggest that ALMS1 should be included in the candidate gene panel for LCA to improve diagnostic efficiency.

Wood dust exposure and the risk of upper aero-digestive and respiratory cancers in males.

BACKGROUND: Wood dust (WD) has been designated a human carcinogen that can cause sino-nasal cancers. However, evidence of its association with other upper aero-digestive tract and respiratory (UADR) cancers is inconsistent. OBJECTIVE: To examine the relationship between WD exposure and the risk of different histological subtypes of UADR cancers. METHODS: In a hospital-based case-control study conducted at Roswell Park Cancer Institute, Buffalo, NY, USA, an examination was carried out to determine the effect of self-reported WD exposure on 1522 male UADR cancer cases (241 oral and oropharyngeal, 90 nasal cavity, nasopharyngeal and hypopharyngeal, 124 laryngeal, 809 lung and tracheal and 258 oesophagus and gastric cardia) and 1522 male controls, frequency matched on age and smoking history. Odds ratios (OR) were calculated after adjusting for relevant risk factors including tobacco smoking. RESULTS: The results show that regular WD exposure was associated with a statistically significant increased risk of 32% for all UADR cancers (OR 1.32; 95% CI 1.01 to 1.77; p-trend = 0.05) and 69% for lung cancer alone (OR 1.69; 95% CI 1.20 to 2.36; p-trend = 0.007). WD was associated with an 82-93% increased risk of squamous cell, small cell and adenocarcinoma of the lung and more than twice the risk of developing squamous cell carcinoma of the nasal cavity, nasopharynx and hypopharynx, with a significant dose-response relationship. Oral and oropharyngeal cancers showed a non-significant increase in risk. A significant increase in risk of laryngeal and lung cancers was noted for subjects regularly exposed to WD for >20 years. Cancers of the oesophagus and gastric cardia did not show any risk associated with WD. WD was associated with a significantly greater risk of UADR cancers among people who had ever smoked than never smokers. CONCLUSION: WD exposure is a potential risk factor for UADR cancers, especially for cancers of the nasal cavity, nasopharynx, larynx and lung.

Decline in research publications from the United Kingdom in anaesthesia journals from 1997 to 2006.

We undertook this survey to identify the trend in the published output of original research in anaesthesia emanating from the United Kingdom (UK) in a 10-year period from 1997 to 2006, inclusive. We examined seven major anaesthetic journals for each of the 10 years, and four other specialist journals for the years 1997, 2000, 2003 and 2006. We included papers on experimental research, randomised controlled clinical trials, large observational studies and case series, formal equipment and apparatus assessments, but we excluded editorials, comments, reviews including systematic reviews, special articles, small case series and case reports, questionnaire surveys of clinical practice and correspondence. We found a highly significant reduction in published research output from the UK in the period under study (% change per year; -5.7 (95% CI -7.4 to -4.0), a trend which was significantly different (p < 0.001) from the trend of changes in research publications worldwide (-1.0% change per year; 95% CI -1.7 to 0.0). We discuss the implications of these findings for UK anaesthesia research strategy.

Hormone replacement therapy as a risk factor for non-small cell lung cancer: results of a case-control study.

PURPOSE: It was the aim of this study to assess the risk of lung cancer in postmenopausal women who received hormone replacement therapy (HRT). EXPERIMENTAL DESIGN: This case-control study involves women who received medical services at Roswell Park Cancer Institute (RPCI) in Buffalo, New York, between 1982 and 1998, and who agreed to complete an epidemiological questionnaire. Participants with missing smoking data were excluded. The case group consisted of 595 women with primary lung cancer. Controls included 1,195 women, randomly selected from a pool of 5,845 eligible individuals, who received medical services at RPCI for non-neoplastic conditions; they had come to RPCI with a suspicion of neoplastic disease, but were diagnosed with neither benign nor malignant conditions. Controls were frequency matched 2:1 to cases on 5-year age intervals and exposure to smoking (ever/never). Cases and controls were comparable for age (means 61.3 and 61.0 years) and ever smoking (90%). RESULTS: There were more former smokers among the cases (67 vs. 59% in controls); cases were less likely to be high school educated, were thinner, and were less likely to report HRT use compared with controls. Overall, hormone use was associated with a significant reduction in risk of lung cancer (adjusted odds ratio = 0.67; 95% confidence interval 0.53-0.85). Stratified analyses showed significant reductions in lung cancer risk in former smokers and women with normal to low body mass index. CONCLUSION: This study supports the hypotheses that there is a protective effect of HRT use on lung cancer risk in women.

MCM2 is an independent predictor of survival in patients with non-small-cell lung cancer.

PURPOSE: Minichromosome maintenance protein 2 (MCM2) is a component of the prereplicative complex. It is essential for eukaryotic DNA replication and is only expressed in proliferating cells. The prognostic utility of MCM2 compared with Ki-67, another marker of proliferating cells, on survival of patients with non-small-cell lung cancer (NSCLC) was studied. PATIENTS AND METHODS: We examined the immunohistochemical expression of MCM2 and Ki-67 in primary pathologic tumor specimens from 221 NSCLC patients. For each marker, the fraction of tumor cells with positive staining was assessed as a percentage and categorized into four groups: 0% to 24%, 25% to 49%, 50% to 74%, and > or = 75%. MCM2 and Ki-67 immunoreactivities were compared with each other, and associations with pathologic and clinical parameters predictive of survival were analyzed with the chi(2) test. Cox regression models were used to assess associations between MCM2 and Ki-67 and survival while controlling for confounders. RESULTS: Independent variables significantly associated with survival were tumor stage, performance status, and staining category. Patients with less than 25% MCM2 immunoreactivity had a longer median survival time than patients with > or = 25% MCM2 immunoreactivity (46 v 31 months; P =.039) and a lower relative risk (RR) of death (RR, 0.55, 95% confidence interval, 0.34 to 0.88). There was no significant association between survival and Ki-67 expression. CONCLUSION: Immunostaining of tumor cells for MCM2 is an independent prognostic parameter of survival for patients with NSCLC. Interpretable results can be obtained on more than 96% of paraffin-embedded specimens, and approximately 35% will be in the favorable subgroup, with less than 25% positively stained tumor cells. Whether MCM2 is predictive of response to therapy needs to be studied.

Homozygosity Mapping in Leber Congenital Amaurosis and Autosomal Recessive Retinitis Pigmentosa in South Indian Families.

Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP) are retinal degenerative diseases which cause severe retinal dystrophy affecting the photoreceptors. LCA is predominantly inherited as an autosomal recessive trait and contributes to 5% of all retinal dystrophies; whereas RP is inherited by all the Mendelian pattern of inheritance and both are leading causes of visual impairment in children and young adults. Homozygosity mapping is an efficient strategy for mapping both known and novel disease loci in recessive conditions, especially in a consanguineous mating, exploiting the fact that the regions adjacent to the disease locus will also be homozygous by descent in such inbred children. Here we have studied eleven consanguineous LCA and one autosomal recessive RP (arRP) south Indian families to know the prevalence of mutations in known genes and also to know the involvement of novel loci, if any. Complete ophthalmic examination was done for all the affected individuals including electroretinogram, fundus photograph, fundus autofluorescence, and optical coherence tomography. Homozygosity mapping using Affymetrix 250K HMA GeneChip on eleven LCA families followed by screening of candidate gene(s) in the homozygous block identified mutations in ten families; AIPL1 - 3 families, RPE65- 2 families, GUCY2D, CRB1, RDH12, IQCB1 and SPATA7 in one family each, respectively. Six of the ten (60%) mutations identified are novel. Homozygosity mapping using Affymetrix 10K HMA GeneChip on the arRP family identified a novel nonsense mutation in MERTK. The mutations segregated within the family and was absent in 200 control chromosomes screened. In one of the eleven LCA families, the causative gene/mutation was not identified but many homozygous blocks were noted indicating that a possible novel locus/gene might be involved. The genotype and phenotype features, especially the fundus changes for AIPL1, RPE65, CRB1, RDH12 genes were as reported earlier.

Regular use of analgesic drugs and ovarian cancer risk.

Analgesics have been shown to reduce risk for colorectal cancer. Results from three recent reports (D. W. Cramer et al., Lancet, 351: 104-107, 1998; C. Rodriguez et. al., Lancet, 352: 1354-1355, 1998; L. Rosenberg et al., Cancer Epidemiol. Biomark. Prev., 9: 933-937, 2000) suggest that these drugs might be associated with decreased risk for ovarian cancer. In this hospital-based case-control study, we compared 547 patients with ovarian cancer to 1094 age-matched patients with nonneoplastic conditions. All of the participants received treatment at the Roswell Park Cancer Institute between 1982 and 1998 and completed a comprehensive epidemiological questionnaire that included information on demographics, life-style factors, and reproductive characteristics as well as frequency and duration of aspirin and acetaminophen use. Women who reported that they had used one or more of these agents at least once a week for at least 6 months were classified as analgesic users. Logistic regression was used to compute crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs). Aspirin users were not at reduced risk of ovarian cancer compared with nonusers (adjusted OR, 1.00; CI, 0.73-1.39). There was also no evidence of a decrease in risk as a function of greater frequency of use or prolonged duration of use. Regular acetaminophen use was associated with a reduced risk (adjusted OR, 0.56; 95% CI, 0.34-0.86), and risk reductions were observed for women with the greatest frequency of use (adjusted OR, 0.32; 95% CI, 0.09-1.08) and longest duration of use (adjusted OR, 0.51; 95% CI, 0.27-0.97). These data suggest that regular use of acetaminophen, but not aspirin, may be associated with lower risk of ovarian cancer.

Adaptation of the diphenylamine (DPA) assay to a 96-well plate tissue culture format and comparison with the MTT assay.

A simple spectrophotometric method for measuring DNA in proliferating cells is described. The method is an adaptation of the widely used diphenylamine (DPA) reaction to examine DNA in cells grown in a 96-well plate. This assay was capable of detecting as little as 10 ng DNA and could be used to measure DNA in stored as well as viable tissue samples. The DPA assay paralleled the MTT (3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay of mitochondrial reductase in A549 cells, a human lung cancer cell line; in EMT6 cells, a mouse breast cancer cell line; and in a primary cell culture of neonatal rat astrocytes. Over several days of proliferative growth in tissue culture, the ratio of MTT to DPA remained constant. Since the DPA assay and MTT assay measured different parameters of the same cells, they could be employed as complementary spectrophotometric assessments of cell growth on a 96-well plates using the same automated enzyme-linked immunosorbent assay plate reader.

Cumulative genetic damage in children exposed to preconception and intrauterine radiation.

Using a mathematical model and newly developed computer software, the data from the Tri-State Leukemia Survey involving different combinations of radiation exposures to the father and mother prior to conception and to the mother during pregnancy were analyzed. The hypothesis that radiation exposure produces genetic damage which may be expressed in the child both as indicator disease and as leukemia was tested. The genetic damage was estimated in terms of the proportion affected by a given exposure. The relative risk of leukemia and certain other indicator diseases among those "affected" could then be estimated. The results were obtained by direct minimization of the total chi-square. The results show that there are at least two distinguishable risk groups, one group with lower (one or two exposures), and the other group with higher (two or three) radiation exposures. The estimates for the proportion affected are 0.13 and .04 for the lower and higher exposure groups, respectively. The relative risks of leukemia and indicator diseases are 25.0 and 5.0, respectively. The 95% confidence intervals for the proportion affected in the lower and higher exposure categories are (.0075, .02) and (.028, .055), respectively, and for the relative risk of leukemia are (16.0, 35.0). These results have confirmed and extended the findings of our preliminary report published in the Journal of the American Medical Association in May 1977.

Epidemiologic differences between women with extraovarian primary peritoneal carcinoma and women with epithelial ovarian cancer.

OBJECTIVE: To describe the epidemiologic features of women with extraovarian primary peritoneal carcinoma and compare them with those of women with primary epithelial ovarian cancer. METHODS: The epidemiologic features of 50 women with extraovarian primary peritoneal carcinoma were compared with those of 503 women with primary epithelial ovarian cancer. We included all women with the respective diagnoses admitted to the Roswell Park Cancer Institute between October 1982 and October 1996 who returned an epidemiologic questionnaire. Epidemiologic features of the study and control groups were extracted from a database compiled from a self-administered questionnaire that has been given to patients as part of the admission process since 1982. Individual variables between the study and control groups were compared using Student t test, chi2 analysis, and Wilcoxon nonparametric test. Two-tailed P < .05 was considered significant. RESULTS: We found few significantly different epidemiologic features between women with extraovarian primary peritoneal carcinoma and those with primary epithelial ovarian cancer. Women with extraovarian primary peritoneal carcinoma were significantly older (mean age 63.8 versus 55.0 years, P < .001), had later menarche (13.3 versus 12.8 years, P = .024), and were less likely to have used perineal talc powder (26.0% versus 48.1%, P = .003). There were no significant differences with respect to reproductive history, contraceptive use, or use of hormone replacement therapy. A larger proportion of ovarian cancer patients reported a family history of breast cancer, but the numbers were too small to reach statistical significance. CONCLUSION: The epidemiologic features of women with extraovarian primary peritoneal carcinoma compared with women with primary epithelial ovarian cancer show few differences. The observed areas of difference warrant further research to determine whether they suggest the occurrence of distinct disease entities.

Hormone replacement therapy as a risk factor for epithelial ovarian cancer: results of a case-control study.

OBJECTIVE: To evaluate the role of hormone replacement therapy (HRT) as a risk factor for the development of epithelial ovarian cancer. METHODS: A case-control study was performed that used 491 patients with epithelial ovarian cancer frequency matched for age at diagnosis (+/-5 years) with a control population of 741 patients with malignancies of nonestrogen-dependent tissues. The odds ratio (OR) for the development of epithelial ovarian cancer was estimated using logistic regression analysis with adjustment for age at diagnosis, parity, oral contraceptive use, smoking history, family history of epithelial ovarian cancer, age at menarche, menopausal status, income, and education. RESULTS: One hundred of 491 patients (20.4%) in the study population had ever used HRT, and 160 of 741 patients (21.6%) in the control population had ever used HRT (OR 0.85; 95% confidence interval [CI] 0.62, 1.2). A significant association between HRT and specific histologic subtypes of epithelial ovarian cancer was not demonstrable for serous cystadenocarcinoma (OR 1.2, 95% CI 0.8, 1.7), Clear cell carcinoma (OR 1.1, 95% CI 0.4, 3.4), or endometrioid carcinoma (OR 0.4; 95% CI 0.2, 1.2). A significant association between duration of use of HRT and the risk of developing epithelial ovarian cancer was not demonstrable for under 5 years (OR 0.8; 95% CI 0.5, 1.2), 5-9 years (OR 0.6; 95% CI 0.3, 1.1), or 10 or more years (OR 0.6; 95% CI 0.3, 1.4). CONCLUSION: A significant association between the use of HRT and the risk of developing epithelial ovarian cancer, even with prolonged exposure, is not demonstrable.

Perineal talc exposure and subsequent epithelial ovarian cancer: a case-control study.

OBJECTIVE: To evaluate the role of talcum powder use as a risk factor for the development of epithelial ovarian cancer. METHODS: In a case-control study, 499 patients with epithelial ovarian cancer were frequency matched for age at diagnosis (-5 years) with a control population of 755 patients. The odds ratio (OR) for the development of epithelial ovarian cancer was estimated using logistic regression analysis with adjustment for age at diagnosis, parity, oral contraceptive use, smoking history, family history of epithelial ovarian cancer, age at menarche, menopausal status, income, education, geographic location, history of tubal ligation, and previous hysterectomy. RESULTS: Two hundred twenty-one of 462 patients (47.8%) in the study population and 311 of 693 patients (44.9%) in the control population had ever used talcum powder (OR 0.92; 95% confidence interval [CI] 0.24, 3.62). A significant association between duration of talc use and development of epithelial ovarian cancer was not demonstrable for 1-9 years (OR 0.9; 95% CI 0.6, 1.5), for 10-19 years (OR 1.4; 95% CI 0.9, 2.2), or for more than 20 years (OR 0.9; 95% CI 0.6, 1.2). To eliminate the possible confounding variable of surgery for the management of ovarian cancer, we omitted 135 patients in the study population who underwent hysterectomy within 5 years of the diagnosis of ovarian cancer. Within this subgroup of patients, tubal ligation or hysterectomy among talc users still failed to demonstrate an increased risk for the development of ovarian cancer (OR 0.9; 95% CI 0.4, 2.2). CONCLUSION: A significant association between the use of talcum powder and the risk of developing epithelial ovarian cancer is not demonstrable, even with prolonged exposure.

Patterns of care survey data on family history and ulcerative colitis in rectal cancer.

Data from a short-term survey on rectal cancer, sponsored by the Commission on Cancer of the American College of Surgeons, were analyzed in order to assess the association between family history of bowel cancer, ulcerative colitis, and rectal cancer. Overall, 7.4% of rectal cancer patients had a positive family history of bowel cancer and 2.5% reported personal history of ulcerative colitis. The association between these two factors was statistically significant. Patients with a positive family history were significantly younger than those without a family history of bowel cancer. Significantly more white patients than black patients had positive family histories. Significantly greater proportions of patients with earlier stage disease and well differentiated tumors were observed among persons with a family history of bowel cancer. No such association was observed among patients with a history of ulcerative colitis.

Reported family history of cancer in 1,271 prostate cancer cases and 1,909 controls.

Prostate cancer risk has been associated with a family history of the disease. A two- to three-fold increase in risk has been observed in several studies. Details concerning modification of this risk by age, type of familial history of prostate cancer, and possible involvement of history of cancer at other sites have been less well documented. This case-control study of 1,271 prostate cancer patients and 1,909 control subjects admitted to Roswell Park Cancer Institute in Buffalo, NY, found age-adjusted increased risk associated with reporting a history of prostate cancer in a father (RR = 2.3, 95% Cl 1.4-3.3) or brother (RR = 2.5, 95% Cl 1.6-3.9). Subjects with both a father and brother affected had a 6.5-fold (95% Cl 1.4-30.5) increased risk of prostate cancer. Greater risk were observed at younger ages of diagnosis. Risks associated with reporting a father or a brother affected were not significantly elevated for patients over age 70 at diagnosis. No significant differences in patients reporting histories of cancer other than prostate cancer were observed regardless of relationship, age at diagnosis, or type of cancer examined. These observations from a large cancer patient population may be useful when making recommendations for cost-effective prostate cancer screening and for directing investigators to the potentially most informative subjects.

National survey of patterns of care for brain-tumor patients.

An excellent response by participating institutions was realized in this survey of patterns of care for patients with primary brain tumors. Since the histopathology of the tumor is such a strong predictor of outcome and influences care so greatly, most analyses were performed not only on the overall series of patients but also by World Health Organization histological classification. Several factors that influence outcome were identified: tumor type, patient age, patient Karnofsky rating, tumor location, and therapy. Very few cases were coded as regards the American Joint Committee on Cancer clinical stage, and few potentially eligible cases were placed in investigative protocols. It behooves those centers providing investigative protocol opportunities to develop liaisons with practicing physicians nearby as well as at some distance and to provide an organizational framework that will make participation in these protocols practical for a larger segment of our brain-tumor patient population. Between 1980 and 1985, the increased use of magnetic resonance imaging in neuroradiology is apparent as well as the increased use of stereotactic biopsy and interstitial radiotherapy. Complications of therapy seem acceptably low. Five-year survival for benign brain tumor is high, while that for the most common primary tumor, glioblastoma multiforme, is only 5.5%. Some of the findings in this survey confirm those from the literature while others, particularly the pattern of care, represent new data.

Pretreatment transurethral resection of prostate cancer and disease-free survival.

Data from the American College of Surgeons' national survey on prostate cancer were analyzed to determine whether recurrence-free survival differs between those patients diagnosed by transurethral resection of the prostate (TURP) and those diagnosed by needle biopsy. Only patients who received radiation therapy as treatment were included in this analysis. There were 461 patients diagnosed by TURP and 541 patients by needle biopsy. Disease free survival was calculated according to the state and tumor differentiation. Except in stage B1, none of the groups showed a statistically significant difference in recurrence-free survival between the two diagnostic procedures. The results of this analysis suggest that the disease-free survival of patients with radiation-treated prostate cancer diagnosed by TURP and needle biopsy are similar.

Intracoronary streptokinase therapy in the coronary care unit for acute myocardial infarction.

Intracoronary streptokinase was offered and preliminary coronary angiography performed in 14 patients who were seen with the clinical diagnosis of acute myocardial infarction within 4 h of onset of symptoms. The procedure was performed in the Coronary Care Unit (CCU) of St. Peter's Medical Center with the use of a portable C-arm fluoroscope. Angiography was recorded on video tape. Service was provided by an "on-call" team consisting of two physicians, a CCU nurse, and a radiology technician, on a 24-h service basis. Adequate visualization of coronary anatomy was obtained in all patients. Patency of occluded vessels was achieved in 10 of 11 patients who received intracoronary streptokinase. The initial streptokinase bolus was administered at a mean interval of 4.1 h from onset of symptoms. It is concluded that speedy and effective coronary thrombolytic therapy can be provided in the CCU on a 24-h service basis by an on-call team. The use of CCU for this purpose will make this therapy widely available across the country, without the need for Cardiac Catheterization Laboratory.

A prospective study of microvascular free-flap surgery and outcome.

Over a 6-month period, 23 members of the International Microvascular Research Group participated in a prospective survey of their microvascular free-flap practice. Data were recorded with each case for 60 variables covering patient characteristics, surgical technique, pharmacologic treatment, and postoperative outcome. A total of 493 free flaps were reported with a representative demographic distribution for age, sex, indications for surgery, risk factors, flap type, surgical technique, and pharmacologic intervention. Mixed effects logistic regression modeling was used to determine predictors of flap failure and associated complications. The overall incidence of flap failure was 4.1 percent (20 of 493). Reconstruction of an irradiated recipient site and the use of a skin-grafted muscle flap were the only statistically significant predictors of flap failure, with increased odds of failure of 4.2 (p = 0.01) and 11.1 (p = 0.03), respectively. A postoperative thrombosis requiring re-exploration surgery occurred in 9.9 percent of the flaps. The incidence of this complication was significantly higher when the flap was transferred to a chronic wound and when vein grafts were needed, with increased odds of failure of 2.9 (p = 0.02) and 2.5 (p = 0.02), respectively. There was a lower incidence of postoperative thrombosis when rectus/transverse rectus abdominis muscle (TRAM) flaps were used, where odds of failure decreased by 0.36 (p = 0.04), and when subcutaneous heparin was administered in the postoperative period, where odds decreased by 0.27 (p = 0.04). There was an overall 69-percent salvage rate for flaps identified with a postoperative thrombosis. Intraoperative thrombosis occurred in 41 cases (8.3 percent) and was observed more frequently in myocutaneous flaps or when vein grafts were needed (5.5 and 5.0 greater odds, respectively; p < 0.001) but was not associated with higher flap failure (2 of 41 cases; 4.9-percent failure rate). The incidence of a hematoma and/or hemorrhage was increased in obese patients and when vein grafts were needed [2.7 (p = 0.02) and 2.6 (p = 0.03) greater odds, respectively], whereas this complication was significantly decreased in muscle flaps (myocutaneous or skin-grafted muscle), in tobacco users, when a heparinized solution was used for general wound irrigation, and when the attending surgeon performed the arterial anastomosis (in contrast to the resident or fellow on staff) (p < 0.05 for each factor). With the multivariable analysis, many factors were found not to have a significant effect on flap outcome, including the recipient site (e.g., head/neck, breast, lower limb, etc.); indications for surgery (trauma, cancer, etc.); flap transfer in extremes of age, smokers, or diabetics; arterial anastomosis with an end-to-end versus end-to-side technique; irrigation of the vessel without or with heparin added to the irrigation solution; and a wide spectrum of antithrombotic drug therapies. These results present a current baseline for free-flap surgery to which future advances and improvements in technique and practice may be compared.

A phase II trial of intraluminal irrigation with recombinant human tissue factor pathway inhibitor to prevent thrombosis in free flap surgery.

A multicenter, multinational, blinded, randomized, parallel-group, phase II study was conducted to investigate the use of recombinant human tissue factor pathway inhibitor (rhTFPI; SC-59735) as an antithrombotic additive to the intraluminal irrigating solution during microvascular anastomosis in free flap reconstructive surgery. A total of 622 patients undergoing free flap reconstruction were randomly assigned to three groups. For each group, a different intraluminal irrigating solution was administered at completion of the microvascular arterial and venous anastomoses and before blood flow to the flap was reestablished: rhTFPI at a concentration of 0.05 or 0.15 mg/ml (low-dose or high-dose group, respectively) or heparin at a concentration of 100 U/ml (current-standard-of-practice group). There were no other differences in treatment among the groups. Patient characteristics, risk factors, and surgical techniques used were similar among all three groups. Flap failure was lower (2 percent) in the low-dose rhTFPI group than in the high-dose rhTFPI (6 percent) and heparin (5 percent) groups, but this difference was not statistically significant (p = 0.069). There were no significant differences in the rate of intraoperative revisions of vessel anastomoses (11 percent, 12 percent, and 13 percent) or postoperative thrombosis (8 percent, 8 percent, and 7 percent) among the low-dose rhTFPI, high-dose rhTFPI, and heparin groups, respectively. The rate of postoperative wound hematoma was significantly lower in the low-dose rhTFPI group (3 percent) than in the high-dose rhTFPI (8 percent) and heparin (9 percent) groups (p = 0.040). There were no differences in blood chemistry or coagulation values among the three study groups. Other than hematomas, there were no differences in the incidence or severity of adverse reactions among the three groups. It is concluded that use of rhTFPI as an intraluminal irrigant during free flap reconstruction is safe, well tolerated, and as efficacious as use of heparin for preventing thrombotic complications during and after the operation. Furthermore, the lower dose of rhTFPI (0.05 mg/ml) may reduce the occurrence of postoperative hematoma and help prevent flap failure.