Food Insecurity in the Elective Enhanced Recovery After Surgery Colorectal Surgical Population: Prevalence and Implications for Surgical Outcomes.

BACKGROUND: Food insecurity is defined as having limited or uncertain availability of nutritionally adequate food. Approximately 10.5% of U.S. households are food-insecure. Our study aimed to determine the prevalence and postoperative implications of food insecurity in a diverse group of colorectal surgery patients admitted to a hospital in an area with a higher-than-average median income. METHODS: The 6-question Household Food Security Survey was added to the colorectal surgery ERAS program preoperative paperwork. Patient demographics, comorbidities, operative parameters, length of stay, and postoperative outcomes were collected by review of electronic medical records. RESULTS: A total of 294 ERAS patients (88.8%) completed the survey over an 11-month period. Thirty-three patients (11.2%) were identified as food-insecure. Food-insecure patients were more likely to be non-white (P = .003), younger (P = .009), smokers (P = .004), chronic narcotic users (P < .001), unmarried (P = .007), and have more comorbidities (P = .004). The food-insecure population had more frequent postoperative ileus (P = .044). Hospital length of stay was significantly longer in food-insecure patients (8.6 days vs 5.4 days, P < .001). Food-insecure patients also had higher rates of >30-day mortality (P = .049). DISCUSSION: Food insecurity was found to occur in patients that lived in communities deemed both affluent and distressed. These patients had longer hospital stays and higher mortality. A food insecurity questionnaire can easily identify patients at risk. Further investigations to mitigate these complications are warranted.

Indications for a "Surgery-First" Approach for the Treatment of Lower Extremity Arterial Disease.

BACKGROUND: In recent years, there has been a tendency toward an "endovascular-first" approach for the treatment for femoropopliteal arterial disease. The purpose of this study is to determine if there are patients that are better served with an initial femoropopliteal bypass (FPB) rather than an endovascular attempt at revascularization. METHODS: A retrospective analysis of all patients undergoing FPB between June 2006 - December 2014 was performed. Our primary endpoint was primary graft patency, defined as patent using ultrasound or angiography without secondary intervention. Patients with <1-year follow-up were excluded. Univariate analysis of factors significant for 5-year patency was performed using χ2 tests for binary variables. A binary logistic regression analysis incorporating all factors identified as significant by univariate analysis was used to identify independent risk factors for 5-year patency. Event-free graft survival was evaluated using Kaplan-Meier models. RESULTS: We identified 241 patients undergoing FPB on 272 limbs. FPB indication was disabling claudication in 95 limbs, chronic limb-threatening ischemia (CLTI) in 148, and popliteal aneurysm in 29. In total, 134 FPB were saphenous vein grafts (SVG), 126 were prosthetic grafts, 8 were arm vein grafts, and 4 were cadaveric/xenografts. There were 97 bypasses with primary patency at 5 or more years of follow-up. Grafts patent at 5 years by Kaplan-Meier analysis were more likely to have been performed for claudication or popliteal aneurysm (63% 5-year patency) as compared with CLTI (38%, P < 0.001). Statistically significant predictors (using log rank test) of patency over time were use of SVG (P = 0.015), surgical indication of claudication or popliteal aneurysm (P < 0.001), Caucasian race (P = 0.019) and no history of COPD (P = 0.026). Multivariable regression analysis confirmed these 4 factors as significant independent predictors of 5-year patency. Of note, there was no statistical correlation between FPB configuration (above or below knee anastomosis, in-situ versus reversed saphenous vein) and 5-year patency. There were 40 FPBs in Caucasian patients without a history of COPD receiving SVG for claudication or popliteal aneurysm that had a 92% estimated 5-year patency by Kaplan-Meier survival analysis. CONCLUSIONS: Long-term primary patency that was substantial enough to consider open surgery as a first intervention was demonstrated in Caucasian patients without COPD, having good quality saphenous vein, and who underwent FPB for claudication or popliteal artery aneurysm.

Incidence of venous thromboembolism in patients with sickle cell disease undergoing noncardiovascular surgery.

OBJECTIVE: Patients with sickle cell disease (SCD) will have a baseline hypercoagulable state and an increased risk of venous thromboembolism (VTE). Few data are available regarding the efficacy of standard prophylaxis in preventing VTE after noncardiovascular surgery for patients with SCD. Our objective was to investigate the incidence of VTE in patients with SCD who had undergone noncardiovascular surgery. METHODS: We performed a retrospective medical record review of 352 patients with SCD who had undergone noncardiovascular surgery from August 2009 to August 2019 at Beaumont Hospitals. An equal number of control patients without SCD were propensity matched for age, sex, race, body mass index, and specific surgery. The data collected included demographics, comorbidities, VTE prophylaxis used, occurrence of deep vein thrombosis (DVT) and pulmonary embolism (PE), hospital length of stay, and 30-day mortality. RESULTS: We found no differences in age, race, sex, ethnicity, operative time, or hospital length of stay between the SCD and propensity-matched control patients. DVT prophylaxis was used more frequently for the SCD patients than for the controls (96.0% vs 88.6%; P < .001). Four SCD patients (1.1%) had developed DVT vs five control patients (1.4%; P > .999). One patient in each group had developed PE (0.3%; P > .999). No difference was found in 30-day mortality between the SCD group and the control group (1 [0.3%] vs 3 [0.9%]; P = .312). Of those with a diagnosis of VTE ≤30 days postoperatively, no differences were present in age, sex, race, BMI, or procedure type. DVT had been diagnosed significantly later in the SCD patients than in the controls (median, postoperative day 12 vs 5; P = .014). None of the five SCD patients with VTE was a smoker compared with four of the six non-SCD patients with VTE, who were current or former tobacco users (P = .061). All the patients who had developed VTE had received DVT prophylaxis at surgery. CONCLUSIONS: We found no differences in the perioperative rates of DVT, PE, or mortality between the SCD patients and matched control patients after noncardiovascular surgery. Vigilant attention to routine VTE prophylaxis seemed to effectively reduce the VTE risk for these hypercoagulable patients. SCD patients might need VTE prophylaxis for a longer period postoperatively compared with those without SCD.

Intramural hematoma of the thoracic aorta: A single-institution, 12-year experience.

OBJECTIVE: The natural history and management of intramural hematoma (IMH) has varied significantly worldwide. From the present retrospective analysis of our institutional database, we have reported the long-term results from medical and surgical management of types A and B IMH. METHODS: Computed tomography reports completed at our tertiary care hospital from July 2007 to July 2020 were used to identify patients with IMH with a thickness of ≥7 mm. Those with IMH directly related to trauma, previous aortic surgery, penetrating atheromatous ulcer, dissection flap, or an iatrogenic source and those who had never received any treatment of IMH at presentation were excluded. RESULTS: A total of 54 patients with IMH had met the inclusion and exclusion criteria. Of the 54 patients, 24 had presented with Stanford type A. Of these 24 patients, 10 had initially undergone surgery and 14 had initially received medical treatment. Two patients in the medical group had subsequently undergone surgery. In addition, 30 patients had presented with type B IMH and had initially received medical treatment, with 3 eventually requiring surgical intervention. In-hospital survival was 90% for type A IMH treated surgically, 93% for type A IMH treated medically, and 97% for type B IMH treated medically. At the last follow-up imaging study of the medically treated patients, 36% of those with type A IMH and 31% of those with type B IMH had experienced complete resolution of IMH at 3.7 and 31.5 months respectively, without surgical intervention. The development of an aortic aneurysm at the site of a previous IMH had occurred in 18% (2 of 11) and 12% (3 of 26) of the type A medical and type B medical cohorts. The overall rate of aortic aneurysm formation in the region of IMH or in another segment was 50%. No difference was found in long-term survival between the three cohorts at a mean follow-up of 22.8 months. CONCLUSIONS: A role appears to exist for medical treatment with anti-impulse therapy for appropriately selected patients with type A IMH. These patients must be followed up closely clinically and radiographically for signs of deterioration in the short- and long-term phases of their care. They can achieve long-term survival similar to that of surgically treated type A IMH and medically treated type B IMH patients using this algorithm. However, they might require late surgical intervention, especially for aneurysmal disease.

Predictors of mortality in nonagenarians undergoing abdominal aortic aneurysm repair: Analysis of the National Surgical Quality Improvement Program dataset.

BACKGROUND: The present study used the American College of Surgeons National Surgical Quality Improvement Program dataset to identify the predictors of 30-day mortality for nonagenarians undergoing endovascular aortic aneurysm repair (EVAR) or open surgical repair (OSR). METHODS: Patients aged >90 years who had undergone abdominal aortic aneurysm repair from 2005 to 2017 were identified using procedure codes. Those with operative times <15 minutes were excluded. The demographics, preoperative comorbidities, and postoperative complications of those who had died by 30 days were compared with those of the patients alive at 30 days. RESULTS: A total of 1356 nonagenarians met the criteria: 1229 (90.6%) had undergone EVAR and 127 (9.4%) had undergone OSR. The overall 30-day mortality was 10.4%. The patients who had died within 30 days were significantly more likely to have undergone OSR than EVAR (40.9% vs 7.2%; P < .001). They also had a greater incidence of dependent functional status (22.0% for those who had died vs 8.1% for those alive at 30 days; P < .001), American Society of Anesthesiology (ASA) classification of ≥4 (81.2% vs 18.8%; P < .001), perioperative blood transfusion (59.6% vs 20.3%; P < .001), postoperative pneumonia (12.1% vs 2.9%; P = .001), mechanical ventilation >48 hours (22.7% vs 2.6%; P < .001), and acute renal failure (12.1% vs 0.5%; P < .001). The EVAR group had a 30-day mortality rate of 2.6% in 1008 elective cases and 28.6% in 221 emergent cases. The OSR group had a 30-day mortality rate of 19.1% in 47 elective cases and 53.7% in 80 emergent cases. In the EVAR cohort, the 30-day mortality group had had a significantly greater incidence of dependent functional status (17% for those who had died vs 8% for those alive at 30 days; P = .004), ASA classification of ≥4 (76.4% vs 40.3%; P < .001), perioperative blood transfusion (57% vs 19%; P < .001), emergency surgery (71% vs 14%; P < .001), and longer operative times (150 vs 128 minutes; P = .001). CONCLUSIONS: Nonagenarians had an incrementally increased, but acceptable, risk of 30-day mortality with EVAR in elective and emergent cases compared with that reported for octogenarians and cohorts of patients not selected for age. We found greater mortality for patients with dependent status, a higher ASA classification, emergent repair, and OSR. These preoperative risk factors could help identify the best surgical candidates. Given these results, consideration for EVAR or OSR might be reasonable for highly selected patients, especially for elective patients with a larger abdominal aortic aneurysm diameter for whom the risk of rupture is higher.

Long-term outcomes and interventions of postoperative type 1a endoleak following elective endovascular aortic aneurysm repair.

OBJECTIVE: This study evaluated the incidence and long-term outcomes of postoperative type 1a endoleak (PT1a) following endovascular aortic aneurysm repair (EVAR). METHODS: A retrospective review of consecutive aortoiliac EVARs performed at a single institution from June 2006 to June 2012 was conducted. Patients with PT1a were identified by postoperative imaging and compared with those who did not develop a PT1a. Late outcomes were also studied of a subset of patients with PT1a who had persistent intraoperative type 1a endoleak (iT1a) on completion angiogram during EVAR that had resolved on initial follow-up imaging. RESULTS: Three hundred eighty-nine patients underwent EVAR with median follow-up of 87 months (interquartile range, 64-111 months). The incidence of PT1a was 8.2% (n = 32) with a median follow-up of 74 months (interquartile range, 52-138 months). Compared with the total cohort, those who developed PT1a were statistically more likely to be female (32% vs 17%; P = .03) and have a higher all-cause mortality (71% vs 40%; P < .01) and aneurysm-related mortality (15.6% vs 1.7%; P < .01). Median time to presentation was 52 months. Of the 32 patients with PT1a, five (15.6%) presented with aortic rupture, of which three underwent extension cuff placement, one had open graft explant, and one declined intervention. Six patients in total (18.7%) declined intervention; five of these died of nonaneurysmal causes and one remains alive. Of the 26 patients with PT1a who had intervention, 21 (80.7%) showed resolution of PT1a, and five (19.2%) had recurrence. For patients with recurrent PT1a, two had resulting aneurysm-related mortality, two endoleaks resolved after relining with an endograft, and one patient declined intervention but remains alive. Patients with PT1a who had intervention with resolution showed no significant difference in median survival estimates (140.0 months) compared with the remaining EVAR cohort (120.0 months; P = .80). Within the PT1a cohort, 6 (18.7%) had also experienced iT1a with a mean time to presentation of the late PT1a of 45 months. iT1a was associated with a significantly increased likelihood of developing a PT1a (P < .01) and decreased median survival (P < .01), but there was no known aneurysm-related mortality. CONCLUSIONS: Development of PT1a following elective EVAR is associated with increased all-cause and aneurysm-related mortality and presents an average of 52 months postoperatively. This underscores the importance of long-term surveillance. Patients with PT1a who had a successful intervention showed no significant difference in median survival. Those with iT1a had a higher risk for PT1a compared with the EVAR cohort overall and had decreased median survival, without increased aneurysm-related mortality.

Vascular invasion predicts advanced tumor characteristics in papillary thyroid carcinoma.

BACKGROUND: The clinical impact of vascular invasion in Papillary Thyroid Carcinoma (PTC) is not well understood. Our aim was to determine if there was an association between vascular invasion and other tumor characteristics and patient outcomes in PTC. METHODS: A retrospective chart review was performed of 536 patients with PTC between January 2007-December 2011. Patient demographics, comorbidities, tumor characteristics, and outcomes were collected. RESULTS: Vascular invasion was associated with lymphatic invasion, capsular invasion, extrathyroidal extension, and the presence of positive lymph nodes. Logistic regression revealed that tumor size was a predictor of vascular invasion. Vascular invasion in PTC tumors was associated with higher tumor recurrence rates, but there were no differences in mortality. CONCLUSION: This study indicates that vascular invasion in PTC is associated with other aggressive pathologic features and an increased recurrence rate. For these reasons, vascular invasion should be an important tumor characteristic when determining extent of treatment.

Genomic variation as a marker of response to neoadjuvant therapy in locally advanced rectal cancer.

There is variation in the responsiveness of locally advanced rectal cancer to neoadjuvant chemoradiation, from complete response to total resistance. This study compared genetic variation in rectal cancer patients who had a complete response to chemoradiation versus poor response, using tumor tissue samples sequenced with genomics analysis software. Rectal cancer patients treated with chemoradiation and proctectomy June 2006-March 2017 were grouped based on response to chemoradiation: those with no residual tumor after surgery (CR, complete responders, AJCC-CPR tumor grade 0, n = 8), and those with poor response (PR, AJCC-CPR tumor grade two or three on surgical resection, n = 8). We identified 195 variants in 83 genes in tissue specimens implicated in colorectal cancer biopathways. PR patients showed mutations in four genes not mutated in complete responders: KDM6A, ABL1, DAXX-ZBTB22, and KRAS. Ten genes were mutated only in the CR group, including ARID1A, PMS2, JAK1, CREBBP, MTOR, RB1, PRKAR1A, FBXW7, ATM C11orf65, and KMT2D, with specific discriminating variants noted in DMNT3A, KDM6A, MTOR, APC, and TP53. Although conclusions may be limited by small sample size in this pilot study, we identified multiple genetic variations in tumor DNA from rectal cancer patients who are poor responders to neoadjuvant chemoradiation, compared to complete responders.

Outcomes in patients with renal hyperparathyroidism requiring cinacalcet pre-operatively followed by parathyroidectomy.

BACKGROUND: Cinacalcet is an effective treatment for renal hyperthyroidism when traditional medical therapy has failed. We studied the impact of pre-operative cinacalcet administration on post-surgical outcomes. METHODS: A retrospective analysis was performed of patients from 2002 to 2017 diagnosed with renal hyperparathyroidism requiring parathyroidectomy to evaluate the need for post-operative supplementation and outcomes. RESULTS: 102 patients were identified; 34 patients were treated with cinacalcet prior to undergoing parathyroidectomy. The cinacalcet treatment cohort (CT) demonstrated a greater duration of renal replacement therapy (p = 0.03) relative to the untreated cohort (NC). NC had greater proportion receiving peritoneal dialysis (p=<0.0001) compared to other forms of renal replacement, greater pre-operative PTH levels (p = 0.001) and greater decrease in PTH after resection (p = 0.0086). Post-operative vitamin D supplementation was more frequent in the CT group (p = 0.02). After propensity matching for pre-operative PTH and duration of renal replacement therapy, there were no differences in post-operative supplementation or outcomes. CONCLUSIONS: Cinacalcet patients may have advanced disease. These patients have longer duration of renal failure and higher PTH levels. After propensity matching, no significant differences were noted in terms of need for supplementation or outcomes.

Solid, Cystic, and Tubular: Novice Ultrasound Skills Training Using a Versatile, Affordable Practice Model.

OBJECTIVE: In spite of the recognized benefits of ultrasound, many physicians have little experience with using ultrasound to perform procedures. Many medical schools and residency programs lack a formal ultrasound training curriculum. We describe an affordable ultrasound training curriculum and versatile, inexpensive practice model. DESIGN: Participants underwent a didactic session to teach the theory required to perform ultrasound-guided procedures. Motor skills were taught using a practice model incorporating analogs of common anatomic and pathologic structures into an opacified gelatin substrate. SETTING: The Marcia and Eugene Applebaum Simulation Learning Institute, Beaumont Hospital, Royal Oak, MI; a private nonprofit tertiary care hospital associated with the OUWB School of Medicine, Rochester, MI. PARTICIPANTS: The model was tested in a cohort of 50 medical students and general surgery residents. RESULTS: The gelatin model can be constructed for $1.03 per learner. The solid, cystic, and vascular structural analogs were readily identifiable on ultrasound and easily differentiated based on their echotextures. Eighty-four percent of participants successfully aspirated the cystic structure, 88% successfully biopsied a portion of the solid structure, and 76% successfully cannulated the tubular structure. Overall, 82% of participants achieved a passing score for the exercise based on a validated Objective Structured Assessment of Technical Skill instrument. There were no significant differences between the medical students and residents. CONCLUSION: This model can be used to teach basic ultrasound skills such as aspiration, biopsy, and vessel cannulation, providing a foundation for the use of ultrasound in a broad range of clinical procedures, as well as providing practice opportunities for medical students and residents to gain increased ultrasound competency and confidence.

Predictors of readmission in nonagenarians: analysis of the American College of Surgeons National Surgical Quality Improvement Project dataset.

BACKGROUND: Increased longevity has led to more nonagenarians undergoing elective surgery. Development of predictive models for hospital readmission may identify patients who benefit from preoperative optimization and postoperative transition of care intervention. Our goal was to identify significant predictors of 30-d readmission in nonagenarians undergoing elective surgery. METHODS: Nonagenarians undergoing elective surgery from January 2011 to December 2012 were identified using the American College of Surgeons National Surgical Quality Improvement Project participant use data files. This population was randomly divided into a 70% derivation cohort for model development and 30% validation cohort. Using multivariate step-down regression, predictive models were developed for 30-d readmission. RESULTS: Of 7092 nonagenarians undergoing elective surgery, 798 (11.3%) were readmitted within 30 d. Factors significant in univariate analysis were used to develop predictive models for 30-d readmissions. Diabetes (odds ratio [OR]: 1.51, 95% confidence interval [CI]: 1.24-1.84), dialysis dependence (OR: 2.97, CI: 1.77-4.99), functional status (OR: 1.52, CI: 1.29-1.79), American Society of Anesthesiologists class II or higher (American Society of Anesthesiologist physical status classification system; OR: 1.80, CI: 1.42-2.28), operative time (OR: 1.05, CI: 1.02-1.08), myocardial infarction (OR: 5.17, CI: 3.38-7.90), organ space surgical site infection (OR: 8.63, CI: 4.04-18.4), wound disruption (OR: 14.3, CI: 4.80-42.9), pneumonia (OR: 8.59, CI: 6.17-12.0), urinary tract infection (OR: 3.88, CI: 3.02-4.99), stroke (OR: 6.37, CI: 3.47-11.7), deep venous thrombosis (OR: 5.96, CI: 3.70-9.60), pulmonary embolism (OR: 20.3, CI: 9.7-42.5), and sepsis (OR: 13.1, CI: 8.57-20.1), septic shock (OR: 43.8, CI: 18.2-105.0), were included in the final model. This model had a c-statistic of 0.73, indicating a fair association of predicted probabilities with observed outcomes. However, when applied to the validation cohort, the c-statistic dropped to 0.69, and six variables lost significance. CONCLUSIONS: A reliable predictive model for readmission in nonagenarians undergoing elective surgery remains elusive. Investigation into other determinants of surgical outcomes, including social factors and access to skilled home care, might improve model predictability, identify areas for intervention to prevent readmission, and improve quality of care.

Barriers to adoption of the surgical resident skills curriculum of the American College of Surgeons/Association of Program Directors in Surgery.

BACKGROUND: The American College of Surgeons (ACS) and the Association of Program Directors in Surgery (APDS) jointly developed a standardized skills curriculum for surgical residents. This program was intended to be affordable, reproducible, reliable, and proficiency-based. Some experts have proposed mandating that all residency programs implement the curriculum. Although general surgery program directors have supported uniformly the use of simulation in training, one third of general surgery residencies have no simulation curricula. Our goal was to identify barriers to the implementation of the ACS/APDS curriculum. METHODS: The ACS/APDS skills curriculum was analyzed on the basis of the ACS website. All materials listed in each module in all 3 phases were tabulated. Supply costs per resident were calculated along with the time requirements for each. RESULTS: The approximate cost per resident for supplies to complete the entire ACS/APDS skills curriculum exceeds $30,000. The initial cost for the development of our surgery learning center was $4.5 million. Capital equipment and instruments were an additional cost. Time to complete the program was 90 h for each resident, with additional time commitments by surgery faculty, simulation center staff, educational development staff, and veterinary staff. Simulation staffing costs were $22,107. CONCLUSION: The ACS/APDS skills curriculum has a substantial resource commitment associated with its implementation. These capital, instrument, and personnel costs present a major challenge to residency programs that want to adopt this program. Faculty participation in the program poses an additional logistic challenge. Last, resident involvement must be scheduled within the 80-h work-week limit, impacting resident availability for their obligations of patient care. Re-examination of the scope and complexity appears warranted, along with development of low-fidelity substitutions for the proposed modules as well as opportunities for resource-sharing.

Sentinel lymph node biopsy in contralateral prophylactic mastectomy: are we overtreating? Experience at a tertiary care hospital.

OBJECTIVE: Use of routine sentinel lymph node biopsy (SLNB) in contralateral prophylactic mastectomy (CPM) is controversial. This retrospective study was undertaken to determine the frequency of SLNB in CPM at a community hospital and its utility as a guide to patient decision making. METHODS: Between 2007 and 2009, 170 patients underwent CPM at a suburban, tertiary care facility. The CPM was either immediate or delayed, or was for ipsilateral recurrent breast cancer. Thirty-seven (21.8%) of 170 patients had SLNB performed with CPM. The mastectomy specimens underwent standard pathologic evaluation by using intraoperative touch preparation cytology and postoperative hematoxylin and eosin staining and immunohistochemistry. RESULTS: No patients who underwent SLNB had positive nodes on touch preparation or final hematoxylin and eosin staining (0/37 [0%]). Fourteen (8.2%) of 37 patients had additional nodes identified in the specimens. These were either axillary tail or intramammary nodes. The median number of SLNs removed was 2 (range, 1-5), none of these were positive. There were 3 incidental cancers diagnosed on final pathology. Two invasive cancers (T1a and grade I) and 1 ductal carcinoma in situ were identified. SLNB was only performed on the patient with DCIS. Neither SLNB nor subsequent axillary lymph node dissection was performed in the invasive cancers. CONCLUSIONS: SLNB was performed in 37 (21.8%) of patients who underwent CPM in a community hospital. Only 3 (1.76%) of 170 patients who underwent CPM had findings on final pathology that would have justified axillary staging. This correlates with other published data regarding SLNB in CPM. Because SLNB is associated with significant morbidity, guidelines for SLNB in prophylactic mastectomy need to be established so to avoid overtreatment.

Changes in inferior vena cava filter placement over the past decade at a large community-based academic health center.

OBJECTIVE: A significant increase in the frequency of inferior vena cava (IVC) filter placement at our large community-based academic health center led us to evaluate changes in indications, devices, and providers over the past decade. METHODS: A single-center retrospective review of all filter placements was performed comparing 76 patients in 1995 with 470 patients in 2005. Demographic data, provider data, filter type, and indications for placement were tabulated. Complications, follow-up evaluation, filter removal, and patient outcomes were examined. RESULTS: There was a greater than sixfold increase in the number of filters placed in 2005 vs 1995. There were no significant differences in patient demographics or the extent of venous thromboembolic (VTE) disease during this period except for an increase in median age. Filter placement by interventional radiologists remained approximately 50% of the total whereas placement by vascular/trauma surgeons increased to 24% and placement by cardiologists decreased to 29% (P < .001). In 2005, a smaller percentage of filters were placed for absolute indications, while filter placements for relative and prophylactic indications increased over the same time period, especially among cardiologists (P = .02). Potentially retrievable filters are increasingly being used for prophylaxis; however, only 2.4% were retrieved. An increasing number of filters were placed in patients with only infrapopliteal deep venous thrombosis (P = .07). A shift was seen to lower profile and removable filter types. Long-term patient follow-up showed little change in disease progression or in morbidity and mortality of filter insertion. CONCLUSIONS: Technological and practice pattern changes have led to an increase in filters inserted by vascular and trauma surgeons in the operating room and intensive care units. Increased diagnosis of VTE disease and newer low profile delivery systems in patients may also have contributed to the significant increase in filter placement. A shift in indications for placement from absolute toward relative indications and prophylaxis is evident over time and across providers, indicating the need for consensus development of appropriate criteria.

Lysyl oxidase expression in bronchogenic carcinoma.

BACKGROUND: Lysyl oxidase catalyzes a key step in the cross-linking of collagen and elastin in the extracellular matrix. Recent studies have documented differential lysyl oxidase expression in the stromal reaction to colon, breast, prostate, and lung cancer. The present study was undertaken to test the hypothesis that lysyl oxidase mRNA and protein expression decrease with advancing tumor stage in patients with bronchogenic carcinoma. METHODS: Tumor specimens were obtained from 17 patients undergoing resection for bronchogenic carcinoma. Real-time polymerase chain reaction was used to determine steady-state lysyl oxidase mRNA expression, and protein expression was qualitatively assessed by immunohistochemistry. RESULTS: Real-time polymerase chain reaction studies documented a 3.4-fold graded decrease in lysyl oxidase mRNA levels as tumors progressed from stage I to IV. Similar qualitative changes in lysyl oxidase protein expression were demonstrated by immunohistochemistry. CONCLUSIONS: These results support the hypothesis that variations in lysyl oxidase expression may correlate with the invasive and metastatic potential of bronchogenic carcinoma.

Nitric oxide-releasing biopolymers inhibit thrombus formation in a sheep model of arteriovenous bridge grafts.

OBJECTIVES: Nitric oxide (NO), produced by normal vascular endothelial cells, reduces platelet aggregation and thrombus formation. NO-releasing biopolymers have the potential to prolong vascular graft and stent patency without adverse systemic vasodilation. METHODS: 5-mm polyurethane vascular grafts coated with a polymer containing the NO-donor dialkylhexanediamine diazeniumdiolate were implanted for 21 days in a sheep arteriovenous bridge-graft model. RESULTS: Eighty percent (4/5) of grafts coated with the NO-releasing polymer remained patent through the 21 day implantation period, compared to fifty percent (2/4) of sham-coated grafts and no (0/3) uncoated grafts. Thrombus-free surface area (+/-SEM) of explanted grafts was significantly increased in NO-donor coated grafts (98.2% +/- 0.9%) compared with sham-coated (79.2% +/- 8.6%) and uncoated (47.2% +/- 5.4%) grafts ( P = .00046). Examination of the graft surface showed no adherent thrombus or platelets and no inflammatory cell infiltration in NO-donor coated grafts, while control grafts showed adherent complex surface thrombus consisting of red blood cells in an amorphous fibrin matrix, as well as significant red blood cell and inflammatory cell infiltration into the graft wall. CONCLUSION: In this study we determined that local NO release from the luminal surface of prosthetic vascular grafts can reduce thrombus formation and prolong patency in a model of prosthetic arteriovenous bridge grafts in adult sheep. These findings may translate into improved function and improved primary patency rates in small-diameter prosthetic vascular grafts.

Lysyl oxidase expression in a rat model of arterial balloon injury.

OBJECTIVE: Traditional therapies for arteriosclerotic disease often fail as a result of an exaggerated fibroproliferative response (recurrent stenosis) at the site of the intervention. Lysyl oxidase, secreted by activated vascular smooth muscle cells and fibroblasts, catalyzes a key step in the cross-linking and stabilization of collagen and elastin in the vascular wall. We hypothesized that lysyl oxidase messenger RNA (mRNA) and protein expression are time-dependent and precede collagen accumulation and luminal narrowing after arterial balloon injury in the rat. METHODS: A 2F balloon-tipped catheter was used to injure the right common carotid artery in male Sprague-Dawley rats. Injured right and control (uninjured) left common carotid arteries were harvested at 0, 0.25, 1, 3, 7, 14, 21, 28, and 60 days for mRNA quantitation and immunohistochemical analysis. Steady-state lysyl oxidase mRNA levels were quantitated with real-time reverse transcription polymerase chain reaction (TaqMan). Immunohistochemical staining with antibodies to alpha-smooth muscle cell actin and lysyl oxidase, and Movat pentachrome staining were performed for qualitative assessment of changes in the cellular and extracellular matrix components of the vessel wall. Post-injury intimal area was measured from hematoxylin and eosin-stained specimens at each time point. RESULTS: When compared with sham-operated control arteries, lysyl oxidase expression in balloon-injured arteries increased significantly to 212% by day 3 after injury, and remained elevated through day 21, with a decrease toward baseline levels by day 28. Lysyl oxidase protein expression did not peak until day 14, and persisted through day 28. Collagen accumulation peaked at day 28, corresponding to the maximal increase in intimal area, with later accumulation of proteoglycans and ground substance in the intimal lesion. CONCLUSION: Our results indicate that lysyl oxidase mRNA and protein expression is time-dependent after balloon injury of the rat carotid artery and that expression appears to precede maximal collagen accumulation and corresponding increases in intimal area. This suggests that lysyl oxidase may have an important role in stabilization of collagen and elastin at sites of vascular injury and that modulation of lysyl oxidase activity may be a viable method to prevent or reduce recurrent stenosis. CLINICAL RELEVANCE: Failure of traditional therapies for ischemic arteriosclerotic disease is often due to an exaggerated fibroproliferative response (recurrent stenosis) at the site of intervention. Recurrent stenosis can be viewed as an injury-repair process, with an initial stage characterized by cellular proliferation followed by deposition of extracellular matrix. This study focuses on lysyl oxidase, a key enzyme involved in stabilization of collagen and elastin. This study demonstrates that lysyl oxidase messenger RNA and protein expression are time-dependent, preceding collagen accumulation and corresponding increases in intimal area. Accumulation of extracellular matrix is a major factor in growth of the restenotic lesion, and modulation of lysyl oxidase activity may offer a therapeutic method for decreasing or preventing recurrent stenosis.