Faculty Bibliography

BACKGROUND:While advancements in surgery and reduced complication rates have made total knee arthroplasty (TKA) one of the most successful and cost-effective procedures in orthopaedic surgery, routine postoperative laboratory tests are still being ordered without evidence as to their necessity. With expansion of the bundled payment models, there may exist an opportunity to cut overall costs while maintaining quality of care by eliminating unnecessary interventions. The objective of this study was to examine the utility of routine postoperative laboratory tests in TKA. METHODS:A retrospective review of 319 TKAs performed at a single institution over a 2-year period was performed. The primary outcomes were the rates of acute blood loss anemia requiring transfusion, acute kidney injury (AKI), electrolyte abnormalities, and 90-day emergency department visits and readmissions. Multivariate logistic regression analysis was also performed to identify the risk factors associated with abnormal laboratory values. RESULTS:89 patients (27.9%) had abnormal postoperative laboratory results, of which 78% were exclusively due to electrolyte (sodium or potassium) abnormalities. The rates of AKI and blood transfusion were 3.8% and 1% respectively. Factors associated with electrolyte abnormalities were abnormal baseline electrolyte levels (p = 0.002 and = 0.006 for sodium and potassium respectively) and anemia (p = 0.049). Factors associated with blood transfusion were ASA score ≥3, preoperative anemia, and no tranexamic acid use. Factors associated with AKI were chronic kidney disease or having at least two of the following: age >65 years, BMI> 35, ASA score ≥3, diabetes, heart disease, and/or anemia. Laboratory results did not change the course of care in 305 of 319 patients (95.6%). There was no increased risk for 90-days ED visits or readmissions with abnormal laboratory values (p = 0.356). CONCLUSION/CONCLUSIONS:With increasing pressure for cost containment in an era of bundled payment models, the very low rate of laboratory associated interventions suggest that routine postoperative laboratory tests is not justified. Obtaining laboratory after primary, unilateral TKA should be driven by patients' risk factors.

OBJECTIVE:Little is known about the natural history and management of aneurysmal aortic arch branch vessels (AABVs). The objectives of this study were to assess the natural history of aneurysmal AABVs and to examine the outcomes of operative intervention. METHODS:A retrospective review of the Yale radiologic database from 1999 to 2016 was performed. Only those patients with an aneurysmal AABV and a computed tomography scan were selected for review. Patients' demographics, aneurysm characteristics, management, and follow-up information were collected. RESULTS:There were 105 patients with 147 aneurysmal AABVs; 76 were male (72%), with a mean age of 70 years (range, 17-93 years). We identified 63 innominate, 50 left subclavian, 30 right subclavian, and 4 common carotid artery aneurysms. On computed tomography, 65 (62%) had aortic aneurysms and six (6%) had suffered an aortic dissection. Most were asymptomatic (104 [99%]); one had chest pain and an enlarging swollen mass. Twelve (11%) patients underwent operative repair (OR) for 12 aneurysmal AABVs because of symptoms, growth, or concomitant aortic operations; 93 (89%) were observed in the no operative repair (NOR) group with cross-sectional imaging. The overall mean vessel diameter was 2.08 ± 0.68 cm. The mean diameters in the OR and NOR groups were 3.32 ± 1.24 cm and 1.97 ± 0.46 cm, respectively (P = .002). OR included nine bypasses with resection, two stent grafts, and one resection without reconstruction. Two patients developed postoperative hemorrhage requiring re-exploration, one patient developed stent thrombosis, and one patient required pseudoaneurysm repair 20 years after index operation. Mean follow-up was 52 ± 51 months for the NOR group, with no ruptures or emboli. The growth rate was 0.04 ± 0.10 cm/y. On multivariable regression analysis, a descending aortic aneurysm (P = .041) and a left subclavian artery aneurysm (P = .016) were associated with higher growth rates, whereas height was associated with a lower growth rate (P = .001). CONCLUSIONS:Aneurysmal AABVs tend to have a benign natural history with slow growth rates and low rates of complications, including rupture and embolization. We recommend expectant observational management for small, incidentally detected aneurysms.