The Journal of Arthroplasty 30 (2015) 43–45
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Mechanical Thromboembolic Prophylaxis With Risk Stratification in Total Knee Arthroplasty William G. Hamilton, MD a, James D. Reeves, MD b, Kevin B. Fricka, MD a, Nitin Goyal, MD a, Gerard A. Engh, MD a, Nancy L. Parks, MS, CCRC a a b
Anderson Orthopaedic Research Institute, Alexandria, Virginia Town Center Orthopaedic Associates, Centreville, Virginia
a r t i c l e
i n f o
Article history: Received 10 March 2014 Accepted 6 August 2014 Keywords: total knee arthroplasty DVT prophylaxis risk stratification continuous passive motion venous thromboembolism
a b s t r a c t The purpose of this study was to determine the rate of thromboembolic and bleeding complications when using mechanical prophylaxis with preoperative risk stratification following total knee arthroplasty (TKA). Between 1994 and 2007, 4037 TKAs were performed on 3144 patients at our institution. Mechanical VTE prophylaxis was used for standard risk patients, which included AV impulse foot pumps, thigh high stockings, and early mobilization. Chemoprophylaxis was only given to patients who were at increased thromboembolic risk. The incidence of DVT identified by ultrasound following TKA was 2.1%. A retrospective review showed 1 patient had a fatal pulmonary embolism, and 5 patients had bleeding complications in the knee. We conclude that mechanical thromboembolic prophylaxis using risk stratification is safe and effective following TKA. © 2014 Elsevier Inc. All rights reserved.
Venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA) remains a controversial topic. Over many years, various regimens have been proposed to prevent deep vein thrombosis (DVT) as well as its sequelae including pulmonary embolus and postthrombotic syndrome. In 2009 the Academy of Orthopaedic Surgeons released recommendations that stratify patients by risk of clotting as well as bleeding complications [1]. This stratification was done in part to address concerns of postoperative bleeding complications when chemotherapeutic agents are used. The current recommendations by the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP) typically advise the combination of a chemotherapeutic agent and mechanical prophylaxis with no consensus or evidenced based data suggesting a “gold standard” agent for prevention of thromboembolic complications [1–5]. Investigators have also questioned the use of DVT rates to measure a regimen’s effectiveness. Authors have argued that no single agent has been shown to reduce the rate of fatal pulmonary embolus which is the catastrophic complication that we wish to avoid [6,7], or postthrombotic syndrome [8]. Data reporting the use of early mobilization [9], mechanical prophylaxis [3], hypotensive anesthesia [10], and risk stratification [11] have supported some clinicians’ desire to avoid agents that tend to cause higher rates of postoperative bleeding [6,7]. In contrast, the ACCP guidelines more strongly recommend the
The Conflict of Interest statement associated with this article can be found at http:// dx.doi.org/10.1016/j.arth.2014.08.006. Reprint requests: Nancy Parks, MS, CCRC, Anderson Orthopaedic Research Institute, P.O. Box 7088, Alexandria, VA 22307. http://dx.doi.org/10.1016/j.arth.2014.08.006 0883-5403/© 2014 Elsevier Inc. All rights reserved.
routine use of chemotherapeutic agents, and cite published data to support this position [4]. At our institution, we have used a regimen of thromboembolic prophylaxis after TKA which includes preoperative risk stratification and a multimodal mechanical program without routine use of a chemotherapeutic agent. This regimen is attractive because it is easy to administer, cost effective, and potentially results in the lowest risk of bleeding of any VTE prevention protocol. The primary objective of this retrospective study was to determine the rate of VTE and bleeding complications in a large cohort of patients at a single institution using isolated mechanical thromboembolic prophylaxis in “standard risk” patients. The secondary objective was to determine whether this approach exposed patients to the increased risk of fatal pulmonary embolus. Methods Between January 1994 and September 2007, 4037 primary total knee arthroplasties were performed by four surgeons at our institution. 2251 patients underwent unilateral TKA. Another 1274 knees were performed as staged bilateral procedures, and 512 knees were performed as simultaneous bilateral procedures. The mean patient age was 67.8 years (range 21–94 years) and average BMI was 30.3 (range 14–54). Forty percent of cases were male. The most common diagnoses were osteoarthritis (94%) and rheumatoid arthritis (3.6%). During this timeframe, hypotensive epidural anesthesia was favored over general anesthesia. Thromboembolic prophylaxis included the combined use of thigh-high anti-embolism stockings, AV impulse foot pumps, and early mobilization. 3501 cases (86.7%) had no prior history of DVT or
44
W.G. Hamilton et al. / The Journal of Arthroplasty 30 (2015) 43–45
any history suggesting hypercoagulability and therefore did not require concomitant use of a chemoprophylactic agent. Thigh-high compression stockings were placed on the non-operative leg prior to surgery in the holding area, and on the operative leg in the operating room at the completion of surgery to hold on the postoperative dressing. A continuous passive motion (CPM) machine (Furniss Corporation, Columbus, OH) was used on the operative extremity in the recovery room, with motion of 70°–110° on the night of surgery, advancing to 0°–110° the following morning (Fig. 1). During hospitalization, patients also wore AV impulse foot pumps (Kendall, Mansfield, Massachusetts) while in bed. On the morning of the first postoperative day, patients began ambulating with a physical therapist; typically receiving two sessions of physical therapy per day during their hospitalization. The length of stay varied throughout the period of study from 2 to 4 days. The use of AV impulse foot pumps was discontinued at the time of discharge. Patients were instructed to continue wearing compression stockings full-time for the first two weeks after surgery after which patients were allowed to take the stockings off at night. Stocking use was fully discontinued at the 4–6 week follow-up appointment. Patient compliance with the foot pump during the hospitalization and the use of the stockings at home was not tracked. For patients at high risk for clotting complications, such as patients who had a history of a prior deep vein thrombosis or pulmonary embolism, thromboembolic prophylaxis also included postoperative chemoprophylaxis such as use of adjusted dose warfarin or low molecular weight heparin. Additionally, any patient who was taking an anticoagulant prior to surgery (including warfarin, aspirin, or plavix) restarted their regimen postoperatively. 536 cases (13.3%) fell into this category of receiving some additional chemoprophylaxis. As per the routine follow-up protocol at our institution at that time, a bilateral lower extremity hip to ankle Doppler ultrasound (Philips, Andover, MA) was performed four- to six-weeks postoperatively at the patient's first postoperative visit. Clinical complications including DVT, pulmonary embolus, and bleeding complications were obtained from our institutional research database; results of the ultrasound studies were obtained from the computer database in the ultrasound department. Chart reviews were also performed to identify any additional clinical complications
not documented in the databases. The incidence of DVT, pulmonary embolus, and bleeding complications requiring return to the operating room was determined from the combination of all these sources. Results 3296 cases (82%) successfully underwent Doppler ultrasound scans at 4–6 weeks following TKA. Ultrasound data were used to diagnose 76 cases with DVT. Six of the clots were labeled as having a chronic appearance at the time of the ultrasound, leaving 70 new cases with 73 clots. The locations of the clots are shown in Table 1, and were most commonly in the calf (22 DVTs), thigh (12), popliteal (11), thigh/popliteal (6), popliteal/calf (4), complete thigh/popliteal/calf (3), and thigh/calf (3). For 12 additional DVTs, the location was unknown. Overall there was a 2.1% incidence of ultrasound-identified DVT following either unilateral or simultaneous bilateral TKA for patients in this study. There were 56 cases with pulmonary emboli (1.4%), including one that was fatal. The fatal case had a chronic DVT that was treated with Coumadin postoperatively. Five patients (0.12%) had bleeding complications. There were three gastrointestinal bleeds, two occurred in patients on Coumadin, and one was in a patient using mechanical prophylaxis only. In addition there were a severe postoperative wound hematoma in one patient on Coumadin, and an acute knee hemarthrosis six months after surgery in one patient. Discussion Thromboembolic prophylaxis following a total knee arthroplasty remains a controversial subject in total joint arthroplasty. Over decades of study, conflicting recommendations have made treatment algorithms difficult to follow. Although the AAOS and ACCP attempted to provide guidelines to help physicians determine the best means of thromboembolic prophylaxis [1,4], no consensus currently exists and surgeons provide different rationales for their prophylaxis choice. The motivating factors for thromboembolic prophylaxis are to protect the patient from a DVT and post-thrombotic syndrome, and most importantly a potentially fatal pulmonary embolus, all while
Fig. 1. A continuous passive motion machine was used on the operative extremity in the postoperative period.
W.G. Hamilton et al. / The Journal of Arthroplasty 30 (2015) 43–45 Table 1 Location and Frequency of DVTs. DVT location
N
calf thigh popliteal thigh/pop pop/calf all thigh/calf unknown TOTAL
22 12 11 6 4 3 3 12 73
minimizing the risk of joint- and limb-threatening bleeding complications in the early postoperative period [6]. While ambiguous and difficult to measure, surgeons also have the incentive to protect themselves from litigation in a situation where there is a fine balance between a thrombotic complication and an adverse bleeding complication. These factors combine to make this clinical decision confusing and highly variable worldwide. We acknowledge several weaknesses of this study. First and foremost, it is a retrospective chart and database review which has its inherent limitations. In addition, we could not control nor account for patients who took other medications, including anti-coagulants such as aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) without our knowledge. Although all cases were seen at the six-week postoperative follow-up visit, we do not have Doppler ultrasound data on the 18% of cases we examined that were healthy, asymptomatic individuals whose insurance did not cover the scan, or those who could not get the scan for scheduling reasons. Unscanned cases were excluded from the denominator of the calculated DVT rate, since we cannot prove that every unscanned case was free of DVT. However we did scan all cases with suspected DVT, and if any VTE event occurred, it was recorded in the database as a complication. We chose to study the early postoperative time interval knowing that most VTE complications occur within 28 days of surgery [13,14]. Use of Doppler ultrasound may not be as sensitive in the detection of DVT as other techniques, such as venogram studies, but our results are comparable to those of others who have used ultrasound for the detection of DVT [11,15]. Our institution has adopted an isolated mechanical prophylaxis algorithm with preoperative risk stratification in order to minimize bleeding complications while giving effective prophylaxis against thromboembolism following TKA. We have used this VTE prevention protocol for nearly 20 years. The 2.1% incidence of DVT and 1.4% incidence of pulmonary embolism reported here are similar to other studies in which chemoprophylactic regimens were used in addition to mechanical prophylaxis [16,17]. Additionally, the complication that is the most catastrophic, a fatal pulmonary embolism, occurred in only one patient who was preoperatively stratified to the high-risk group and placed on Coumadin postoperatively secondary to a chronic lower extremity DVT. In a study of 3473 consecutive TKA's using a similar mechanical protocol to the one described in this paper with the addition of aspirin for chemoprophylaxis, Lotke and Lonner et al reported a 0.26% incidence of nonfatal PE, a 0.4% incidence of reoperations for hematoma, and an incidence of fatal PE between 0.06% and 0.14% [16]. Similarly, in a study of 4060 patients undergoing hip or knee arthroplasty also using aspirin for chemoprophylaxis, Cusick and Beverland et al reported a 0.33% incidence of above the knee DVT, a 0.66% incidence of non-fatal symptomatic PE, and a fatal PE rate of 0.07% [17]. The use of preoperative risk stratification to identify patients at higher risk for VTE complications has been supported by the AAOS as
45
well as published data [2,11]. Dorr and Gendelman et al used a multimodal approach following total joint arthroplasty in which the thromboprophylactic regimen was selected according to patient risk factors [11]. Their data in 1046 low risk patients compare favorably to ours: no fatal pulmonary emboli, a 0.3% incidence of non-fatal pulmonary emboli, and a 3.9% overall rate of ultrasound-identified DVT. Data from the current study indicate that our patients were not exposed to an increased rate of dangerous VTE complications as suggested by other authors [12]. It should also be clarified that chemoprophylaxis per se does not put patients at higher risk, but rather that with risk stratification, there is a selection bias for higherrisk patients to be on chemoprophylaxis. While our sense is that the exclusion of a chemoprophylactic agent is not accepted by a large number of surgeons at the current time, we believe that by using the technique of risk stratification, a multimodal mechanical regimen without a chemotherapeutic agent can be safely used following TKA. This approach has led to not only a low incidence of DVT and pulmonary embolism in our institution, but a very low incidence of postoperative bleeding. This regimen is cost-effective as well as easy to administer, providing an additional option for clinicians to consider.
References 1. Johanson NA, Lachiewicz PF, Lieberman JR, et al. American Academy of Orthopaedic Surgeons clinical practice guideline on prevention of symptomatic pulmonary embolism in patients undergoing total hip or knee arthroplasty. J Bone Joint Surg Am 2009;91(7):1756. 2. Haas SB, Barrack RL, Westrich G, et al. Venous thromboembolic disease after total hip and knee arthroplasty. J Bone Joint Surg Am 2008;90(12):2764. 3. Eisele R, Kinzl L, Koelsch T. Rapid-inflation intermittent pneumatic compression for prevention of deep venous thrombosis. J Bone Joint Surg Am 2007;89(5):1050. 4. Geerts WH, Bergqvist D, Pineo GF, et al. Prevention of venous thromboembolism: American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest 2008;133(6 Suppl.):381S. 5. Pour AE, Keshavarzi NR, Purtill JJ, et al. Is venous foot pump effective in prevention of thromboembolic disease after joint arthroplasty: a meta-analysis. J Arthroplasty 2013;28(3):410. 6. Callaghan JJ, Dorr LD, Engh GA, et al. Prophylaxis for thromboembolic disease: recommendations from the American College of Chest Physicians—are they appropriate for orthopaedic surgery? J Arthroplasty 2005;20(3):273. 7. Burnett RS, Clohisy JC, Wright RW, et al. Failure of the American College of Chest Physicians-1A protocol for lovenox in clinical outcomes for thromboembolic prophylaxis. J Arthroplasty 2007;22(3):317. 8. Lonner JH, Frank J, McGuire K, et al. Postthrombotic syndrome after asymptomatic deep vein thrombosis following total knee and hip arthroplasty. Am J Orthop 2006;35(10):469. 9. Pearse EO, Caldwell BF, Lockwood RJ, et al. Early mobilisation after conventional knee replacement may reduce the risk of postoperative venous thromboembolism. J Bone Joint Surg (Br) 2007;89(3):316. 10. Hu S, Zhang ZY, Hua YQ, et al. A comparison of regional and general anaesthesia for total replacement of the hip or knee: a meta-analysis. J Bone Joint Surg (Br) 2009; 91(7):935. 11. Dorr LD, Gendelman V, Maheshwari AV, et al. Multimodal thromboprophylaxis for total hip and knee arthroplasty based on risk assessment. J Bone Joint Surg Am 2007;89(12):2648. 12. Eikelboom JW, Karthikeyan G, Fagel N, et al. American Association of Orthopedic Surgeons and American College of Chest Physicians guidelines for venous thromboembolism prevention in hip and knee arthroplasty differ: what are the implications for clinicians and patients? Chest 2009;135(2):513. 13. Bjornara BT, Gudmundsen TE, Dahl OE. Frequency and timing of clinical venous thromboembolism after major joint surgery. J Bone Joint Surg (Br) 2006;88(3):386. 14. Warwick D, Friedman RJ, Agnelli G, et al. Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement when compared with the time course of thromboembolic events: findings from the Global Orthopaedic Registry. J Bone Joint Surg (Br) 2007;89(6):799. 15. Lotke PA, Ecker ML, Alavi A, et al. Indications for the treatment of deep venous thrombosis following total knee replacement. J Bone Joint Surg Am 1984; 66(2):202. 16. Lotke PA, Lonner JH. The benefit of aspirin chemoprophylaxis for thromboembolism after total knee arthroplasty. Clin Orthop Relat Res 2006;452:175. 17. Cusick LA, Beverland DE. The incidence of fatal pulmonary embolism after primary hip and knee replacement in a consecutive series of 4253 patients. J Bone Joint Surg (Br) 2009;91(5):645.
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Mechanical Thromboembolic Prophylaxis With Risk Stratification in Total Knee Arthroplasty William G. Hamilton, MD a, James D. Reeves, MD b, Kevin B. Fricka, MD a, Nitin Goyal, MD a, Gerard A. Engh, MD a, Nancy L. Parks, MS, CCRC a a b
Anderson Orthopaedic Research Institute, Alexandria, Virginia Town Center Orthopaedic Associates, Centreville, Virginia
a r t i c l e
i n f o
Article history: Received 10 March 2014 Accepted 6 August 2014 Keywords: total knee arthroplasty DVT prophylaxis risk stratification continuous passive motion venous thromboembolism
a b s t r a c t The purpose of this study was to determine the rate of thromboembolic and bleeding complications when using mechanical prophylaxis with preoperative risk stratification following total knee arthroplasty (TKA). Between 1994 and 2007, 4037 TKAs were performed on 3144 patients at our institution. Mechanical VTE prophylaxis was used for standard risk patients, which included AV impulse foot pumps, thigh high stockings, and early mobilization. Chemoprophylaxis was only given to patients who were at increased thromboembolic risk. The incidence of DVT identified by ultrasound following TKA was 2.1%. A retrospective review showed 1 patient had a fatal pulmonary embolism, and 5 patients had bleeding complications in the knee. We conclude that mechanical thromboembolic prophylaxis using risk stratification is safe and effective following TKA. © 2014 Elsevier Inc. All rights reserved.
Venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA) remains a controversial topic. Over many years, various regimens have been proposed to prevent deep vein thrombosis (DVT) as well as its sequelae including pulmonary embolus and postthrombotic syndrome. In 2009 the Academy of Orthopaedic Surgeons released recommendations that stratify patients by risk of clotting as well as bleeding complications [1]. This stratification was done in part to address concerns of postoperative bleeding complications when chemotherapeutic agents are used. The current recommendations by the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP) typically advise the combination of a chemotherapeutic agent and mechanical prophylaxis with no consensus or evidenced based data suggesting a “gold standard” agent for prevention of thromboembolic complications [1–5]. Investigators have also questioned the use of DVT rates to measure a regimen’s effectiveness. Authors have argued that no single agent has been shown to reduce the rate of fatal pulmonary embolus which is the catastrophic complication that we wish to avoid [6,7], or postthrombotic syndrome [8]. Data reporting the use of early mobilization [9], mechanical prophylaxis [3], hypotensive anesthesia [10], and risk stratification [11] have supported some clinicians’ desire to avoid agents that tend to cause higher rates of postoperative bleeding [6,7]. In contrast, the ACCP guidelines more strongly recommend the
The Conflict of Interest statement associated with this article can be found at http:// dx.doi.org/10.1016/j.arth.2014.08.006. Reprint requests: Nancy Parks, MS, CCRC, Anderson Orthopaedic Research Institute, P.O. Box 7088, Alexandria, VA 22307. http://dx.doi.org/10.1016/j.arth.2014.08.006 0883-5403/© 2014 Elsevier Inc. All rights reserved.
routine use of chemotherapeutic agents, and cite published data to support this position [4]. At our institution, we have used a regimen of thromboembolic prophylaxis after TKA which includes preoperative risk stratification and a multimodal mechanical program without routine use of a chemotherapeutic agent. This regimen is attractive because it is easy to administer, cost effective, and potentially results in the lowest risk of bleeding of any VTE prevention protocol. The primary objective of this retrospective study was to determine the rate of VTE and bleeding complications in a large cohort of patients at a single institution using isolated mechanical thromboembolic prophylaxis in “standard risk” patients. The secondary objective was to determine whether this approach exposed patients to the increased risk of fatal pulmonary embolus. Methods Between January 1994 and September 2007, 4037 primary total knee arthroplasties were performed by four surgeons at our institution. 2251 patients underwent unilateral TKA. Another 1274 knees were performed as staged bilateral procedures, and 512 knees were performed as simultaneous bilateral procedures. The mean patient age was 67.8 years (range 21–94 years) and average BMI was 30.3 (range 14–54). Forty percent of cases were male. The most common diagnoses were osteoarthritis (94%) and rheumatoid arthritis (3.6%). During this timeframe, hypotensive epidural anesthesia was favored over general anesthesia. Thromboembolic prophylaxis included the combined use of thigh-high anti-embolism stockings, AV impulse foot pumps, and early mobilization. 3501 cases (86.7%) had no prior history of DVT or
44
W.G. Hamilton et al. / The Journal of Arthroplasty 30 (2015) 43–45
any history suggesting hypercoagulability and therefore did not require concomitant use of a chemoprophylactic agent. Thigh-high compression stockings were placed on the non-operative leg prior to surgery in the holding area, and on the operative leg in the operating room at the completion of surgery to hold on the postoperative dressing. A continuous passive motion (CPM) machine (Furniss Corporation, Columbus, OH) was used on the operative extremity in the recovery room, with motion of 70°–110° on the night of surgery, advancing to 0°–110° the following morning (Fig. 1). During hospitalization, patients also wore AV impulse foot pumps (Kendall, Mansfield, Massachusetts) while in bed. On the morning of the first postoperative day, patients began ambulating with a physical therapist; typically receiving two sessions of physical therapy per day during their hospitalization. The length of stay varied throughout the period of study from 2 to 4 days. The use of AV impulse foot pumps was discontinued at the time of discharge. Patients were instructed to continue wearing compression stockings full-time for the first two weeks after surgery after which patients were allowed to take the stockings off at night. Stocking use was fully discontinued at the 4–6 week follow-up appointment. Patient compliance with the foot pump during the hospitalization and the use of the stockings at home was not tracked. For patients at high risk for clotting complications, such as patients who had a history of a prior deep vein thrombosis or pulmonary embolism, thromboembolic prophylaxis also included postoperative chemoprophylaxis such as use of adjusted dose warfarin or low molecular weight heparin. Additionally, any patient who was taking an anticoagulant prior to surgery (including warfarin, aspirin, or plavix) restarted their regimen postoperatively. 536 cases (13.3%) fell into this category of receiving some additional chemoprophylaxis. As per the routine follow-up protocol at our institution at that time, a bilateral lower extremity hip to ankle Doppler ultrasound (Philips, Andover, MA) was performed four- to six-weeks postoperatively at the patient's first postoperative visit. Clinical complications including DVT, pulmonary embolus, and bleeding complications were obtained from our institutional research database; results of the ultrasound studies were obtained from the computer database in the ultrasound department. Chart reviews were also performed to identify any additional clinical complications
not documented in the databases. The incidence of DVT, pulmonary embolus, and bleeding complications requiring return to the operating room was determined from the combination of all these sources. Results 3296 cases (82%) successfully underwent Doppler ultrasound scans at 4–6 weeks following TKA. Ultrasound data were used to diagnose 76 cases with DVT. Six of the clots were labeled as having a chronic appearance at the time of the ultrasound, leaving 70 new cases with 73 clots. The locations of the clots are shown in Table 1, and were most commonly in the calf (22 DVTs), thigh (12), popliteal (11), thigh/popliteal (6), popliteal/calf (4), complete thigh/popliteal/calf (3), and thigh/calf (3). For 12 additional DVTs, the location was unknown. Overall there was a 2.1% incidence of ultrasound-identified DVT following either unilateral or simultaneous bilateral TKA for patients in this study. There were 56 cases with pulmonary emboli (1.4%), including one that was fatal. The fatal case had a chronic DVT that was treated with Coumadin postoperatively. Five patients (0.12%) had bleeding complications. There were three gastrointestinal bleeds, two occurred in patients on Coumadin, and one was in a patient using mechanical prophylaxis only. In addition there were a severe postoperative wound hematoma in one patient on Coumadin, and an acute knee hemarthrosis six months after surgery in one patient. Discussion Thromboembolic prophylaxis following a total knee arthroplasty remains a controversial subject in total joint arthroplasty. Over decades of study, conflicting recommendations have made treatment algorithms difficult to follow. Although the AAOS and ACCP attempted to provide guidelines to help physicians determine the best means of thromboembolic prophylaxis [1,4], no consensus currently exists and surgeons provide different rationales for their prophylaxis choice. The motivating factors for thromboembolic prophylaxis are to protect the patient from a DVT and post-thrombotic syndrome, and most importantly a potentially fatal pulmonary embolus, all while
Fig. 1. A continuous passive motion machine was used on the operative extremity in the postoperative period.
W.G. Hamilton et al. / The Journal of Arthroplasty 30 (2015) 43–45 Table 1 Location and Frequency of DVTs. DVT location
N
calf thigh popliteal thigh/pop pop/calf all thigh/calf unknown TOTAL
22 12 11 6 4 3 3 12 73
minimizing the risk of joint- and limb-threatening bleeding complications in the early postoperative period [6]. While ambiguous and difficult to measure, surgeons also have the incentive to protect themselves from litigation in a situation where there is a fine balance between a thrombotic complication and an adverse bleeding complication. These factors combine to make this clinical decision confusing and highly variable worldwide. We acknowledge several weaknesses of this study. First and foremost, it is a retrospective chart and database review which has its inherent limitations. In addition, we could not control nor account for patients who took other medications, including anti-coagulants such as aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) without our knowledge. Although all cases were seen at the six-week postoperative follow-up visit, we do not have Doppler ultrasound data on the 18% of cases we examined that were healthy, asymptomatic individuals whose insurance did not cover the scan, or those who could not get the scan for scheduling reasons. Unscanned cases were excluded from the denominator of the calculated DVT rate, since we cannot prove that every unscanned case was free of DVT. However we did scan all cases with suspected DVT, and if any VTE event occurred, it was recorded in the database as a complication. We chose to study the early postoperative time interval knowing that most VTE complications occur within 28 days of surgery [13,14]. Use of Doppler ultrasound may not be as sensitive in the detection of DVT as other techniques, such as venogram studies, but our results are comparable to those of others who have used ultrasound for the detection of DVT [11,15]. Our institution has adopted an isolated mechanical prophylaxis algorithm with preoperative risk stratification in order to minimize bleeding complications while giving effective prophylaxis against thromboembolism following TKA. We have used this VTE prevention protocol for nearly 20 years. The 2.1% incidence of DVT and 1.4% incidence of pulmonary embolism reported here are similar to other studies in which chemoprophylactic regimens were used in addition to mechanical prophylaxis [16,17]. Additionally, the complication that is the most catastrophic, a fatal pulmonary embolism, occurred in only one patient who was preoperatively stratified to the high-risk group and placed on Coumadin postoperatively secondary to a chronic lower extremity DVT. In a study of 3473 consecutive TKA's using a similar mechanical protocol to the one described in this paper with the addition of aspirin for chemoprophylaxis, Lotke and Lonner et al reported a 0.26% incidence of nonfatal PE, a 0.4% incidence of reoperations for hematoma, and an incidence of fatal PE between 0.06% and 0.14% [16]. Similarly, in a study of 4060 patients undergoing hip or knee arthroplasty also using aspirin for chemoprophylaxis, Cusick and Beverland et al reported a 0.33% incidence of above the knee DVT, a 0.66% incidence of non-fatal symptomatic PE, and a fatal PE rate of 0.07% [17]. The use of preoperative risk stratification to identify patients at higher risk for VTE complications has been supported by the AAOS as
45
well as published data [2,11]. Dorr and Gendelman et al used a multimodal approach following total joint arthroplasty in which the thromboprophylactic regimen was selected according to patient risk factors [11]. Their data in 1046 low risk patients compare favorably to ours: no fatal pulmonary emboli, a 0.3% incidence of non-fatal pulmonary emboli, and a 3.9% overall rate of ultrasound-identified DVT. Data from the current study indicate that our patients were not exposed to an increased rate of dangerous VTE complications as suggested by other authors [12]. It should also be clarified that chemoprophylaxis per se does not put patients at higher risk, but rather that with risk stratification, there is a selection bias for higherrisk patients to be on chemoprophylaxis. While our sense is that the exclusion of a chemoprophylactic agent is not accepted by a large number of surgeons at the current time, we believe that by using the technique of risk stratification, a multimodal mechanical regimen without a chemotherapeutic agent can be safely used following TKA. This approach has led to not only a low incidence of DVT and pulmonary embolism in our institution, but a very low incidence of postoperative bleeding. This regimen is cost-effective as well as easy to administer, providing an additional option for clinicians to consider.
References 1. Johanson NA, Lachiewicz PF, Lieberman JR, et al. American Academy of Orthopaedic Surgeons clinical practice guideline on prevention of symptomatic pulmonary embolism in patients undergoing total hip or knee arthroplasty. J Bone Joint Surg Am 2009;91(7):1756. 2. Haas SB, Barrack RL, Westrich G, et al. Venous thromboembolic disease after total hip and knee arthroplasty. J Bone Joint Surg Am 2008;90(12):2764. 3. Eisele R, Kinzl L, Koelsch T. Rapid-inflation intermittent pneumatic compression for prevention of deep venous thrombosis. J Bone Joint Surg Am 2007;89(5):1050. 4. Geerts WH, Bergqvist D, Pineo GF, et al. Prevention of venous thromboembolism: American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest 2008;133(6 Suppl.):381S. 5. Pour AE, Keshavarzi NR, Purtill JJ, et al. Is venous foot pump effective in prevention of thromboembolic disease after joint arthroplasty: a meta-analysis. J Arthroplasty 2013;28(3):410. 6. Callaghan JJ, Dorr LD, Engh GA, et al. Prophylaxis for thromboembolic disease: recommendations from the American College of Chest Physicians—are they appropriate for orthopaedic surgery? J Arthroplasty 2005;20(3):273. 7. Burnett RS, Clohisy JC, Wright RW, et al. Failure of the American College of Chest Physicians-1A protocol for lovenox in clinical outcomes for thromboembolic prophylaxis. J Arthroplasty 2007;22(3):317. 8. Lonner JH, Frank J, McGuire K, et al. Postthrombotic syndrome after asymptomatic deep vein thrombosis following total knee and hip arthroplasty. Am J Orthop 2006;35(10):469. 9. Pearse EO, Caldwell BF, Lockwood RJ, et al. Early mobilisation after conventional knee replacement may reduce the risk of postoperative venous thromboembolism. J Bone Joint Surg (Br) 2007;89(3):316. 10. Hu S, Zhang ZY, Hua YQ, et al. A comparison of regional and general anaesthesia for total replacement of the hip or knee: a meta-analysis. J Bone Joint Surg (Br) 2009; 91(7):935. 11. Dorr LD, Gendelman V, Maheshwari AV, et al. Multimodal thromboprophylaxis for total hip and knee arthroplasty based on risk assessment. J Bone Joint Surg Am 2007;89(12):2648. 12. Eikelboom JW, Karthikeyan G, Fagel N, et al. American Association of Orthopedic Surgeons and American College of Chest Physicians guidelines for venous thromboembolism prevention in hip and knee arthroplasty differ: what are the implications for clinicians and patients? Chest 2009;135(2):513. 13. Bjornara BT, Gudmundsen TE, Dahl OE. Frequency and timing of clinical venous thromboembolism after major joint surgery. J Bone Joint Surg (Br) 2006;88(3):386. 14. Warwick D, Friedman RJ, Agnelli G, et al. Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement when compared with the time course of thromboembolic events: findings from the Global Orthopaedic Registry. J Bone Joint Surg (Br) 2007;89(6):799. 15. Lotke PA, Ecker ML, Alavi A, et al. Indications for the treatment of deep venous thrombosis following total knee replacement. J Bone Joint Surg Am 1984; 66(2):202. 16. Lotke PA, Lonner JH. The benefit of aspirin chemoprophylaxis for thromboembolism after total knee arthroplasty. Clin Orthop Relat Res 2006;452:175. 17. Cusick LA, Beverland DE. The incidence of fatal pulmonary embolism after primary hip and knee replacement in a consecutive series of 4253 patients. J Bone Joint Surg (Br) 2009;91(5):645.
