Commentary

As Venturi et al state, venous thromboembolism (VTE) is often both a silent and potentially deadly complication. In many instances, VTE is also preventable, which is especially true for surgical patients. Any discussion of the dreaded complications of deep vein thrombosis (DVT) or pulmonary embolism (PE) is a welcome contribution to the progress that is slowly being made in persuading plastic surgeons to appropriately use thromboprophylaxis in their patients.

An important feature of the preceding article is its explanation of some of the changes for VTE prevention made by the American College of Chest Physicians (ACCP) in its 2008 guidelines (eighth edition)1 compared with the earlier seventh edition in 2004.2 This important publication is based on a consensus of experts and a critical literature review of clinical trials that represent the best evidence currently available. Each recommendation is accompanied by its grade of evidence according to clinical study design and resulting risk–benefit ratio. All documents associated with the publication of the ACCP recommendations are lengthy and dense, but they have historically been embraced by national oversight and certification bodies as the gold standard for clinical practice with respect to VTE prevention and treatment.

Unfortunately, too few plastic surgeons followed the ACCP's seventh edition guidelines correctly and they will be even less enthusiastic about the new recommendations. In the eighth edition, the ACCP recommends that determining the level of risk for a DVT or PE should be based on the type of surgical procedure performed, rather than individual patient risk factors. One reason for the change is that randomized trials of VTE prevention and treatment typically investigate one group of patients (eg, those undergoing total hip replacement, thoracic surgery, abdominal procedures, etc). This is the approach used to determine the safety, efficacy, and indications of all drugs, and the system has worked well.

The ACCP does say that individual risk factors for VTE must be considered, just as risk factors for other types of possible complications should be identified. However, they also state that counting the number of risk factors is not supported by recent scientific evidence. In addition, little is known about how risk factors may interact. It makes sense that a higher number of risk factors translates to a higher risk for VTE, but the effect may be exponential, not simply cumulative.

Despite the change in approach presented by the ACCP in its eighth edition guidelines, Venturi et al propose the adoption of an individual risk scale that lists individual risk factors and their scores, so that patients can be assigned to a risk group. Curiously, this form seems also to serve as an order for VTE prophylaxis based on the score. In my practice, the patient history and information regarding risk factors has been gathered well before surgery and patients who will receive chemoprophylaxis are instructed to bring their medications with them to the hospital.

We use a risk assessment instrument in my practice in an attempt to identify patients with risk factors who are having a procedure that would not typically demand chemoprophylaxis. Unless there is a contraindication (such as high risk for bleeding), patients receive preventive anticoagulant therapy for all lower trunk procedures: abdominoplasty, panniculectomy, circumferential bodylift, abdominoplasty combined with another procedure, liposuction of the lower body, and thighplasty. In light of the eighth edition recommendations, our protocols need to be adjusted.

One of the more significant changes in the 2008 ACCP guidelines relates to the use of chemoprophylaxis. The ACCP defines a low-risk surgical patient as one having minor surgery. In the past, the ACCP has used the term “minor” to mean a procedure lasting less than one hour.2 “Major” surgery is a procedure with general or regional anesthesia that lasts at least one hour or (as Venturi et al explain) a procedure performed under local anesthetic or sedation that lasts two hours or more. In the new guidelines, surgery patients not having a minor procedure should receive either low molecular weight heparin (LMWH), low-dose unfractionated heparin (LDUH), or fondaparinux. This encompasses a large proportion of plastic surgery patients.

In the “risk group definitions” portion of the VDC order form in the Appendix of the article by Venturi et al, the authors describe moderate- and high-risk patients as those “having surgery requiring admission and recovery in the hospital.” A DVT/PE Prophylaxis Survey conducted by the American Society for Aesthetic Plastic Surgery (ASAPS) in late 2008 revealed that 73% of 417 survey respondents perform at least some abdominoplasties as an outpatient procedure (unpublished data). When asked where they routinely perform abdominoplasties, 29% of surgeons answered “office,” 50% said “surgery center,” and 54% responded “hospital” (multiple responses were allowed). If followed, the guidelines presented by Venturi et al would leave at least half of abdominoplasty patients without appropriate VTE prophylaxis because they are not admitted to a hospital. Another problem with the risk group definitions is that “low risk” equates to “healthy patients having outpatient surgery.” A healthy patient may have risk factors and/or undergo surgery in a hospital. To be useful, these group definitions need refinement.

An additional modification in the ACCP guidelines is the movement to three risk classification groups (low, moderate, and high) based on procedure type, versus four groups in 2004 (low, moderate, high, and highest) based on individual level of risk. Like many others, Venturi et al have appropriately changed to three risk groups in this current article, but they still seem to be focused on individual risk factors, and the VDC form is very similar to those presented in their previous publications.3, 4, 5 In a recent Venturi article,3 for example, chemoprophylaxis with enoxaparin would be ordered only for the “highest risk” group (with more than four risk factors). Therefore, a 43-year-old obese woman undergoing an abdominoplasty (with or without another procedure) would receive prophylaxis only with intermittent pneumatic compression (IPC) devices and compression stockings. Based on their new risk assessment form, this same patient now would receive enoxaparin, which is appropriate for moderate- and high-risk procedures and patients.6, 7

Near the end of their article, Venturi et al state that the use of anticoagulants for all at-risk patients “will result in increased bleeding complications,” which is the primary reason plastic surgeons give for not using chemoprophylaxis. The ACCP has found no evidence to suggest that this is true when drug instructions are followed correctly.1, 2 In my practice, fondaparinux is the anticoagulant we use most often. At first, we tended to begin prophylaxis too soon after surgery and encountered a few instances of excessive bleeding. Today, we typically begin the drug on postoperative day one, after the patient has been checked for any unusual postoperative bleeding, and continue for 10 days in patients who have undergone body contouring of the lower trunk. Since adopting this approach, only one of our patients had a hematoma that required open evacuation following a panniculectomy (which is not an unusual complication without prophylaxis). In one circumferential bodylift patient, we stopped enoxaparin after one dose because of excessive drain output, and that patient later developed a PE. The duration of chemoprophylaxis for general surgery patients is still being debated. We do know, however, that the period of highest risk for a PE in surgical patients is between three and seven postoperative days. It seems prudent that an anticoagulant should at least extend throughout this period, especially given the fact that approximately one-third of patients with a PE die before they are diagnosed.

Other plastic surgeons have reported no significant difference in bleeding complications when chemoprophylaxis is properly used in patients undergoing transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction (pedicled and free flaps, both immediate and delayed procedures).8, 9 One study continued enoxaparin for seven postoperative days,9 and the other primarily used subcutaneous unfractionated heparin until the patient was discharged.8 We have not typically used anticoagulants for breast reconstruction patients. However, we have had three female patients—all of whom used IPCs only—develop a DVT in the past two years after the placement of tissue expanders.

The 2008 ACCP guidelines related to cancer contain much stronger wording than previous editions, with the current recommendation stating that “cancer patients undergoing surgery should receive aggressive thromboprophylaxis.” This is because cancer patients undergoing surgery have at least twice the risk of postoperative DVT and more than three times the risk of fatal PE than noncancer patients having a similar procedure. All cancer patients, as a group, have a six-fold increased risk of VTE plus a significantly lower survival rate. Unfortunately, any differences between patients with active versus previous cancer are not discussed, probably because data are lacking. One would think that all procedures involving flaps also demand chemoprophylaxis, even those in patients without cancer.

As the Venturi et al article mentions, mechanical prophylaxis with intermittent pneumatic compression has been dropped from the 2008 ACCP recommendations unless a patient has a high bleeding risk and cannot receive an anticoagulant. IPC may also be used as an adjunct to an anticoagulant in high-risk patients. This means that IPC alone are no longer considered adequate prophylaxis for moderate or high-risk patients or procedures. The reason for the change is the lack of controlled studies that have produced grade 1 evidence of efficacy for IPCs or venous foot pumps. Such devices are not always fitted properly, compliance is difficult to assess, and blinding is nearly impossible. Although these types of mechanical prophylaxis should not be used in patients with peripheral vascular disease, they are otherwise considered safe, without side effects, and unlikely to cause harm.

The DVT/PE Prophylaxis Survey of ASAPS members in late 2008 asked surgeons about their VTE prevention measures and the types of procedures they perform: truncal body contouring, breast procedures (reconstruction, reduction, mastopexy, and augmentation), facelift, brachioplasty, and thighlift. Nearly 99% of respondents said they use DVT/PE prophylaxis, which sounds impressive. However, fewer than 30% reported using LMWH (the drug most often prescribed) for a circumferential body lift. Only 18% said they used LMWH for abdominoplasty, with 21% using it for abdominoplasty combined with other procedures (unpublished data). A few surgeons say they use dextran and/or aspirin for prophylaxis, neither of which is appropriate.

The prevention of DVT and PE has become a national healthcare priority and performance measure being stressed by The Joint Commission and the National Quality Forum (NQF). This measure will look for the proportion of patients who receive appropriate VTE prophylaxis within 24 hours before or after surgery based on the ACCP guidelines. Data will also be collected regarding the incidence of possibly preventable VTE. With The Joint Commission and NQF endorsing such measures, we can assume that the American Association for Accreditation of Ambulatory Surgery Facilities (AAAASF) will soon follow. Based on the recent ASAPS survey results showing that compression devices are typically the only form of VTE prophylaxis, most plastic surgeons and the facilities where they work will be out of compliance with national recommendations unless education improves and attitudes change. As a specialty, plastic surgeons need to address whether we should continue making up our own rules about important patient safety issues or adhere to guidelines established by a consensus of experts who know a great deal more about VTE than we do.