Commentary on: Doppler ultrasound imaging of plastic surgery patients for deep venous thrombosis detection: a prospective controlled study.

The author of the preceding article has done a creditable job of presenting a prospective cohort study of Doppler ultrasound screening for lower extremity deep venous thrombosis (DVT) of patients undergoing cosmetic outpatient surgery procedures. Not surprisingly, no cases of postoperative DVT were noted among the postoperative patients. While we may wonder about the cost implications of universal Doppler screening before and after cosmetic surgery, the investigator demonstrates that the modality was feasible in their practice, albeit it was offered free of charge. However, more troubling are a number of other assertions by the author that gloss over important issues surrounding postoperative venous thromboembolism (VTE) risk assessment and prevention in plastic surgery patients. Although they are rare events, VTEs do occur after outpatient operations. In an analysis of 259,231 outpatient surgeries over a 5-year period from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database, Pannucci and colleagues calculated an overall VTE rate of 0.15%, including cases of DVT and pulmonary embolus (PE). The investigators identified multiple risk factors for VTE, including age, body mass index (BMI), and length of surgery. A weighted risk index was calculated based on these factors. Using this index, a sub-population of high-risk patients was noted to have a 30-day VTE rate of 1.18%.While wewould all like to believe that postoperative VTE poses little or no risk to our outpatients, the “never seen one” rationale does not justify ignoring preoperative VTE risk assessment or, in high-risk cases, failure to consider VTE prophylaxis. In the current article, the author asserts that “it remains impossible to accurately predict which patients will develop a postoperative deep venous thrombosis.” He goes on to dismiss the Caprini Risk Assessment Model (RAM) as lacking validity and maintains that “Risk stratification is ineffective in plastic surgery patients.” Recent studies on VTE risk assessment would seem to indicate otherwise. It is true that when created in the early 1990s, the Caprini RAM was based on expert opinion and was initially applied in concert with logic and best clinical judgment. However, since that time, the Caprini model has been validated in multiple patient populations. Most recently, a 2010 validation study of a Caprini-based RAM by Bahl and colleagues retrospectively evaluated 8216 general, vascular, and urologic surgery patients from the NSQIP database. Patients were scored by the Caprini RAM criteria, and 30-day postoperative VTE events were recorded. Investigators noted that the scoring system, which assigns patients to 1 of 4 categories from low to highest risk, was predictive of VTE events: Higher Caprini scores were associated with greater risks of postoperative VTE. Patients with Caprini scores of 9 or higher were noted to have a VTE risk of 6.51%. The Caprini RAM has also been found to predict 30-day VTE risk in a series of 2106 patients undergoing otolaryngology or head and neck surgery. Contrary to the current study author’s claims, the Caprini model has also been validated for plastic surgery patients.