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Abstracts
Journal of Vascular Surgery July 2017
compared with extracranial cervical artery dissection without pseudoaneurysm. Antiplatelet or anticoagulant treatment is equally effective in pseudoaneurysm resolution, prevention and symptom relief. This may be one of the best sequential imaging studies regarding this disease entity currently available.
Association of Very Low-Volume Practice With Vascular Surgery Outcomes in New York Mao J, Goodney P, Cronenwett J, Sedrakyan A. JAMA Surg 2017 May 17;doi:10.1001/jamasurg.2017.1100. Conclusions: Open abdominal aortic aneurysm repair (OAR) and carotid endarterectomy (CEA) procedures performed by very low-volume surgeons resulted in worse postoperative outcomes and greater lengths of stay. Although the percentage of very low-volume surgeons declined from 2000 to 2014, it remains concerning that any such providers provide such care given ready access to higher-volume surgeons. Future research is needed to understand the existence of this practice pattern in other surgical fields. Efforts to eliminate this practice pattern are warranted to ensure high-quality care for all patients. Summary: The objective of this study was to investigate the existence and outcomes of open abdominal aortic aneurysm repair (OAR) and carotid endarterectomy (CEA) performed by very low-volume surgeons in New York. The authors thought that the shift in these procedures to an endovascular technique might impact surgical volumes and results. Prior studies based on Medicare or multicenter data are affected by inaccurate information related to individual surgeons so a comprehensive state-level database was chosen to minimize incomplete information. This observational cohort study used the inpatient data stored in the New York State Department Planning and Research Cooperative System, an all age and all payer database for every hospital discharge in New York. Each surgeon has a unique identifier to allow information collection regarding the specific surgeon over time in the database, irrespective of the hospital where the surgeon practiced. The study period extended from 2000 to 2014. Only elective procedures were included, as physicians may not have been able to transfer urgent or emergent cases. To ensure homogeneous comparisons, patients who underwent OAR and a concurrent procedure for aorta dissection or thoracic aneurysm, visceral or renal bypass, endovascular aneurysm repair, or major cardiac surgery (eg, valve surgery or coronary artery procedures) were excluded as were those who underwent CEA and a concurrent carotid stenting or major cardiac surgery. The definition of a very low volume surgeon was one who performed one or less of the designated procedures on average per year. Average annual surgeon volume was obtained by dividing the total designated procedures performed by the total number of years in which the surgeon performed at least one procedure. Those who performed one or less procedures every year on average were classified as very low-volume surgeons. In the calculation of average annual volume, procedures performed concurrent to other operations and during both elective and emergent/urgent admissions were included. Vascular surgeons were those doing more than 75% vascular specific, cardiac surgeons as those doing more than 20% cardiac surgery and all others as general/other surgeons (including neurosurgeons). Patient demographics included age, gender, race/ethnicity, primary insurance and comorbidities. Institutional characteristics were hospital location and hospital volume of the designated procedures with an average per hospital calculated to allow categorization into tertiles. The primary outcome of the study was inpatient safety, including perioperative mortality, acute myocardial infarction (AMI) and stoke. Other outcomes included in-hospital sepsis, shock, length of stay (LOS), total charges adjusted to 2014 US dollars and 30 day readmission into the hospital. Prolonged LOS and excessive charges were defined as more than the 75th percentile for comparison. In adjusted analysis, three models to assess differences in outcomes between patients treated by very low volume surgeons and those treated by higher-volume surgeons for OAR and CEA were used. Model 1 used logistic regression and only adjusted for patient characteristics, including age, sex, race/ethnicity, insurance status, procedure year, and major comorbidities. Model 2 and model 3 used a generalized linear mixed model to account for surgeon and hospital clustering as random effects. Model 2 additionally adjusted for surgeon specialty and accounted for surgeon clustering. Model 3 was a fully adjusted model, controlling for all
patient, surgeon, and facility characteristics and accounting for both surgeon and hospital clustering. Subgroup analyses were conducted to compare outcomes of patients treated by very low-volume surgeons with those treated by surgeons in low-volume (but performed more than 1 procedure per year), medium-volume, and high volume tertiles, determined by surgeons’ average annual volume of the specific procedure. All P values were two-sided, and a P value < .05 was regarded as significant. There were 8781 OAR procedures and 68,896 CEA procedures during the study period and included in the study. The mean (SD) patient age was 71.7 (8.4) years for OAR and 71.5 (9.1) years for CEA. A total of 614 surgeons performed OAR and 1071 performed CEA in New York during the study period. Of these, 318 (51.8%) and 512 (47.8%), respectively, were very low-volume surgeons. Very low-volume surgeons were less likely to be vascular surgeons for both OAR (23.9% vs 63.9%; P < .001) and CEA (14.6% vs 51.7%; P < .001). The number and proportion of very low-volume surgeons decreased over the years. Regarding open aneurysm repair, those treated by very low volume surgeons were younger (mean age, 70.1 vs 71.8 years; P ¼ .001), more likely to have Medicaid (5.1% vs 1.8%; P < .001), and less likely to be white (84.5% vs 90.7%; P < .001) and performed in low-volume hospitals (66.3% vs 30.6%; P < .001) compared with patients treated by highervolume surgeons. Very low-volume surgeons had higher postoperative mortality (6.7% vs 3.5%; P < .001), higher risks of sepsis or shock (5.7% vs 3.7%; P ¼ .008), more likely to have a prolonged LOS (eg, $ 9 days; 39.3 % vs 30.1%; P < .001) and higher hospital charges (median cost, $54,660 vs $49,156; P < .001). When fully adjusting for patient, surgeon, and facility characteristics, patients treated by very low-volume surgeons had a twofold higher odds of postoperative death (odds ratio [OR], 2.09; 95% confidence interval [CI], 1.41-3.08) compared with those treated by higher volume surgeons. Odds of sepsis or shock (OR, 1.45; 95% CI, 0.95-2.20), prolonged LOS (OR, 1.37; 95% CI, 1.11-1.70), and 30day readmission (OR, 1.19; 95% CI, 0.93-1.54) were also higher among patients treated by very low-volume surgeons. Regarding CEA results, those treated by very low volume surgeons were less likely to be white (81.3% vs 89.8%; P < .001), more likely to have Medicaid insurance (5.8% vs 2.9%; P < .001) and be performed in low-volume hospitals (53.4% vs 33.3%; P <.001). Patients who had a CEA performed by very low-volume surgeons had higher risk of experiencing postoperative AMI (1.5% vs 0.5%; P < .001), stroke (3.5% vs 2.1%; P ¼ .003), and 30-day readmission (11.5% vs 8.5%; P ¼ .002) as well as a longer LOS (median, 2 vs 1 day; P <.001) and higher hospital charges (median cost, $15 290 vs $16 349; P < .001). After adjusting for all patient, surgeon, and facility characteristics, patients treated by very low-volume surgeons experienced a 1.8fold higher odds of experiencing AMI (OR, 1.83; 95% CI, 1.03-3.26), stroke (OR, 1.78; 95% CI, 1.21-2.62), excessive charges (OR, 1.28; 95% CI, 1.01-1.62) and 30-day readmission (OR, 1.30; 95% CI, 1.04-1.62). Subgroup analysis reflected the overall findings. For example, patients undergoing OAR performed by very low-volume surgeons were more likely to have higher mortality and more frequent prolonged LOS and 30-day readmission, even compared to those treated by surgeons in the lowest volume tertile. Comment: Training and experience results in improved outcomes, once again demonstrated by this study regarding “bread and butter” vascular surgical procedures. Patient should mandate vascular care by the experts, and in particular vascular surgery by vascular surgeons who are active in their trade.
Decubitus Ulcers in Patients Undergoing Vascular Operations Do Not Influence Mortality But Affect Resource Utilization Mehaffey JH, Politano AD, Bhamidipati CM, Tracci MC, Cherry KJ, Kern, JA, et al. Surgery 2017;161:1720-7. Conclusions: Contrary to common perception, perioperative decubitus ulceration does not adversely affect mortality after vascular operation in patients proceeding to operative intervention. Patients with decubitus ulcers are, however, at higher risk for complications and incur sizeable additional charges. Summary: Although the authors anticipate that decubitus ulcers are detrimental to outcomes after vascular surgery operations, the influence of perioperative decubitus ulcers in contemporary vascular surgery is essentially unknown. Data for this study was abstracted from
Journal of Vascular Surgery
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331
Volume 66, Number 1 the 2009 Nationwide Inpatient Sample (NIS), which is the largest Healthcare Cost and Utilization Project (HCUP) all-payer inpatient database and is sponsored by the Agency for Healthcare Research and Quality (AHRQ). Patients were selected based on whether they underwent open or endovascular carotid repair, open abdominal aortic aneurysm repair, femoral artery to distal vessel revascularization, endovascular peripheral arterial stenting or above and/or below knee amputation and all 15 procedure codes were queried. Only patients over 18 years of age were selected. Cases with multiple procedural codes were assigned to groups based on the first procedure code. Patients with ruptured aneurysms were excluded. Records were selected only once per any given group (based on operative procedure) and were examined with the intent to perform a comprehensive analysis of the null hypothesis. Patient risk factors were assessed using 30 different AHRQ comorbidities as developed by Elixhauser. The presence or absence of a decubitus ulcer (DU) separated the groups. Body mass index was required for several analyses so was also queried. In-hospital mortality, complications, and discharge disposition after major vascular operation were the outcomes of interest. Complications were identify and aggregate into several categories, including stroke, wound healing, postoperative infection, renal, pulmonary, gastrointestinal, cardiovascular, systemic, and procedural. The method of analysis was a case-mix adjusted hierarchical mixed-models analysis that examined in-hospital mortality, the occurrence of any complication, and discharge disposition. A total of 538,808 cases were analyzed of which 16,000 had DU. Decubitus ulcers were most prevalent among Caucasian male Medicare beneficiaries (P < .001). Decubitus ulcer patients also underwent more nonelective vascular operations (P < .001). Wound, infectious, and procedural complications were more common in patients with decubitus ulcers (P < .001). Failure to rescue, defined as mortality after any complication, was more than doubled in patients with decubitus ulcers (nondecubitus ulcers, 1.5%; decubitus ulcers, 3.2%; P < .001). Similarly, unadjusted mortality was 2.3-fold higher in patients undergoing vascular operation with decubitus ulcers (nondecubitus ulcers, 3%, decubitus ulcers, 6%; P < .001). Patients with DU had prevalence 1.5 times higher of having 2 or more complications and had a longer duration of stay by a mean of 10 days. However, after risk adjustment among all patients, neither the presence of a decubitus ulcer nor specific ulcer staging increased the adjusted odds of death. In patients with a DU, independent predictors of mortality included in descending order: paralysis, electrolyte disorder, liver disease, nonelective admission, CHF, renal failure and increasing age but diabetes, neurologic disorders and hypertension reduced the odds of death. The impact of procedure demonstrated that carotid endarterectomy increased while peripheral stent reduced the risk of mortality. Regarding the adjusted risk of developing any complication in patients with DU, those associated with a higher risk were chronic pulmonary disease, paralysis, CHF, electrolyte disorder, nonelective admission, being female and increasing age. Open and endovascular abdominal aortic repair and, to a lesser degree, femoral-distal arterial stent increased the adjusted risk of developing any complication. Having a decubitus ulcer increased the adjusted odds of discharge to an intermediate care facility (odds ratio 2.9; P < .001). These patients also had 1.6 times the total charges compared to their nondecubitus ulcer cohort (nondecubitus ulcers: $49,460 6 $281 vs decubitus ulcers: $81,149 6 $5,855; P < .001). Comments: Having a decubitus ulcer, as an independent factor, does not increase the mortality of patients undergoing a vascular surgical procedure. However, healthy patients rarely have a decubitus ulcer and so many other debilitating diseases are present in patients with DU and the risk of complications, discharge to a care facility and overall costs are dramatically increased. Certainly, extra and diligent care must be provided to these patients to have an optimal outcome.
Lower Extremity Bypass Surgery on Patients Transferred From Other Hospitals Is Associated With Increased Morbidity and Mortality Aziz F, Chu Y, Lehman EF. Ann Vasc Surg 2017;41:205-13. Conclusions: Multiple factors affect an interfacility transfer of patients including advanced age, need for emergency procedure and contaminated wounds. Patients who are transferred from another institution for
a lower extremity bypass surgery are at a substantially higher risk for postoperative morbidity and mortality. Summary: The objective of this study is to define the incidence of interfacility transfer among patients who underwent lower extremity bypasses and to find the preoperative factors associated with interhospital transfer. In addition, the authors aim to find the incidence of perioperative morbidity and mortality among these patients and compare this cohort with patients who were directly admitted from home. The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) was used to generate the data for this manuscript. All patients who underwent any lower extremity open revascularization during 2013 were identified using the Procedure-Targeted Participant Use Data File from the NSQIP database. Any patient who presented with bilateral limb revascularization in the same year was deleted. The primary outcome was mortality. Secondary outcomes included length of hospital stay (LOS) over 30 days, significant postoperative bleeding, myocardial infarction (MI) or stroke, progressive renal insufficiency and readmission within 30 days. Basic demographic data included age, gender, race, and body mass index. Several perioperative variables were analyzed: operative times, length of hospital stay, type of operation, symptoms, high-risk physiologic factors, high-risk anatomic factors, preoperative use of aspirin, preoperative use of beta blockers, preoperative use of statins, need for amputation, significant postoperative bleeding, postoperative MI, postoperative stroke, untreated loss of patency, wound infection, preoperative albumin level, number of days from hospital admission to operation, type of anesthetic, American Society of Anesthesiologists (ASA) classification, diabetes mellitus, end-stage renal disease, emergency operation, congestive heart failure (CHF), chronic obstructive pulmonary disease, hypertension, postoperative renal failure, need for reoperation, history of smoking, surgeon’s specialty, need for blood transfusion, transfer status, urinary tract infection, wound classification, cardiac arrest, wound disruption, superficial and deep wound infection, pneumonia, and need for reintubation. The details of the statistical method are well described in the manuscript. Logistic regression was used to look for bivariate associations of being transferred with postoperative outcomes such as mortality, LOS >30 days, and significant postoperative bleeding. These analyses were carried out in 3 ways: unadjusted without covariates included in the models, adjusted for age, emergency procedure, and wound infection by including those variables as covariates in the model, and using a reduced data set of subjects matched one-to-one for transfers and nontransfers based on propensity scores generated from a logistic regression model using age, emergency procedure, and wound infection to predict transfer status. A significant P value was < .05. A total of 2646 patients undergoing lower extremity bypass surgery were discovered with mean age of 67.7 (611.3) years. A total of 2,359 patients (89%) were admitted from home, and a total of 287 patients were transferred from acute care hospital inpatient (4%), nursing home/chronic care/intermediate care facility (3%), from outside emergency department (3%), and from other (1%). Those preoperative variables found to be significantly associated with being transferred using bivariate analysis using logistic regression were: emergency procedure (odds ratio [OR], 4.76; 95% confidence interval (CI), 3.31-6.86; P < .001), ASA score of 4-5 (OR, 3.78; 95% CI, 1.71-8.34; P < .001), transfusion over 4 units of packed red blood cells (pRBCs) in 72 hours before surgery (OR, 3.62; 95% CI, 1.91-6.84; P < .001), dirty/infected wound (OR, 2.40; 95% CI, 1.21-4.73; P < .003), clean/contaminated wound (OR, 2.27; 95% CI, 1.21-4.23; P <.003), age (over 85 years old: OR, 2.09; 95% CI, 1.35-3.23; P < .001), history of CHF 30 days prior to surgery (OR, 1.85; 95% CI, 1.00-3.42; P < .049), presence of high-risk physiologic factors (OR, 1.70; 95% CI, 1.29-2.23; P < .001), and open wound/wound infection (OR, 1.53; 95% CI, 1.19-1.96; P < .001). Patients with femoral to distal bypasses and pop to distal bypasses were more likely to be transferred as compared to those patients who underwent femoral to popliteal bypasses (ORs, 1.7 and 1.6; Cis, 1.3-2.2 and 1.03-2.39; P < .05). Using multivariable analysis the factors found to be significantly associated with being transferred were: age over 85 years old (OR, 2.24; 95% CI, 1.39-3.61; P < .003), emergency surgery (OR, 5.51; 95% CI, 3.63-8.36; P < .001), dirty/ infected wound (OR, 2.77; 95% CI, 1.36-5.65; P < .022), open wound and wound infection (OR, 1.38; 95% CI, 1.03-1.84; P < .033). Based on the multivariable analysis, a predicted probability of being transferred was calculated for each significant variable. The probability of transfer was 7.2% for patients without any risk factors, 8.8% for patients who were between 75 and 85 years old, 14.8% for patients who were over 85 years old, 30.1%