Abstract
The incidence of venous thromboembolism (VTE) after hip and knee major surgery without prophylaxis ranges from 29% to 60% for deep vein thrombosis (DVT) and from 1% to 3% for fatal pulmonary embolism (PE) 1 –3 ; consequently, thromboprophylaxis in this clinical setting is strongly recommended by experts and international consensus guidelines. 3 Conversely, limited information is available on the rate of VTE complications and thromboprophylaxis use in other orthopaedic surgeries, such as shoulder arthroscopy. 4 To the best of our knowledge, the incidence and risk factors for VTE in shoulder arthroscopy haven’t been investigated in prospective epidemiological studies. Some independent, retrospective, observational studies and case series have reported a quite low VTE rate in shoulder arthroscopy 5 –12 ; moreover, a few information is available on the safety and efficacy of thromboprophylaxis in this setting. Thus, current guidelines on the prevention of VTE in patients undergoing orthopedic surgery do not have a specific recommendation for those undergoing shoulder arthroscopy. 3
In the recently published RECOS registry, we prospectively evaluated the incidence of symptomatic VTE following different types of shoulder surgery (arthroscopy, hemiarthroplasty, total replacement, and fixation for proximal humeral fracture. 13 Furthermore, risk factors for VTE and thromboprophylactic practices in this population have also been analyzed.
Here, we report the results of the RECOS registry in the specific group of patients undergoing shoulder arthroscopy. Study protocol and inclusion and exclusion criteria were already explained in a previous publication. 13 Briefly, from June 2009 to June 2011, 9 Italian centers participated in the registry and 1366 patients were enrolled. For each included patients, demographic characteristics, data regarding surgery, use of antithrombotic prophylaxis, potential VTE risk factors, and symptomatic objectively diagnosed VTE during 90 days follow-up were recorded. The decision to initiate thromboprophylaxis (as well as type, dose, and duration) was left to the investigators. Due to the low incidence (0.66%) of VTE in the whole population, only the following common potential VTE risk factors were evaluated for this study: gender, age, duration of surgery > 60 minutes, and body mass index (BMI) > 30 kg/m2.
For the study purpose, the incidence of VTE after surgery in the whole population, and in the subgroups of patients in which antithrombotic prophylaxis was or was not prescribed, was assessed. Furthermore, results of subgroup analyses of patients with and without potential risk factors for VTE were presented to characterize subgroups at particular high or low risk of VTE. Incidences of VTE at the end of follow-up in the whole population and in specific subgroups were provided as percentages with the corresponding 95% confidence intervals (with continuity correction).
Of the whole population, 982 (71.9%) patients underwent shoulder arthroscopy. The description of demographic and clinical features of the analyzed population is reported in Table 1; 54.8% of patients were males and about 20% of patients were prescribed a thromboprophylactic treatment, always with low-molecular-weight heparins at prophylactic dose (<5700 UI/once daily); in most (90%) of the patients the recommended duration of prophylaxis was > 10 days (Table 1). After 90 days of follow-up, 3 patients had symptomatic VTE, resulting in a cumulative incidence rate of 0.31% (95% confidence interval [CI] 0.08-0.98). Two patients had lower limb proximal DVT and 1 patient had symptomatic, not fatal PE (Table 2); the diagnosis was confirmed by compressive ultrasonography in all the cases of DVT and by computed lung tomography in the patient with clinical suspicion of PE. Thromboprophylaxis was not prescribed in none of the patients having VTE complications. However, the incidence rate of VTE appeared extremely low even in the subgroup of patients in which antithrombotic prophylaxis was not prescribed (0.39%, 95% CI 0.01-1.23). Mean age was significantly higher in patients with VTE than in patients without VTE (67.1 +/3.49 years vs 55.6 ± 0.42 years, respectively; P = .024), although the incidence of VTE was low and not significantly different in the groups of patients younger and older than 55 years (0% vs 0.62%; P = 0.24). Incidence of VTE appeared similar in male and female patients (0.19% vs 0.45%; P = 0.59), in patients with BMI < or ≥ 30 kg/m2 (0.34% vs 0%; P = 1.00), and in patients with duration of surgery > or ≤ 60 minutes (0.42% vs 0.27%; P = 1.00).
Demographic and Clinical Features of the Analyzed Population.
Abbreviations: BMI, body mass index; VTE, venous thromboembolism; COPD, chronic obstructive pulmonary disease; IBD, inflammatory bowel disease.
aMedical diseases include heart failure, COPD, rheumatological disorders, and IBD.
Clinical Features of Patients With VTE.
Abbreviations: M, male; F, female; BMI, body mass index; DVT, deep vein thrombosis; VTE, venous thromboembolism.
To our knowledge, this is the first, prospective, large multicenter study that investigates the risk of DVT and PE in patients undergoing shoulder arthroscopy; in our study, the rate of symptomatic VTE was quite low, being about 0.3% at 3 months. Previous studies gave inconsistent results. In a small prospective study, Takahashi et al 14 found an asymptomatic DVT rate of 5.7% in 175 patients who underwent a shoulder arthroscopy. Of note, all patients had an upper and lower limb vein ultrasonographic evaluation for DVT screening and used elastic stockings or foot pumps for VTE prophylaxis. Conversely, in an Italian multicentric survey evaluating 9285 different arthroscopic procedures performed between 2005 and 2006, Randelli et al 11 found an incidence of symptomatic DVT of 0.08%. Furthermore in a 42-month period analysis of UK national database, the incidence of VTE within 90 days after arthroscopic procedures appeared extremely low (0.01% in 65302 patients. 15 However, results of this study should be interpreted with caution, since only VTE events occurring during surgical admission or requiring hospitalization within 90 days after surgery have been recorded. Finally, a recent meta-analysis assessed the rate of VTE following surgery of the shoulder and elbow. 16 In this study including 14 published articles (mainly retrospective and case series) for a total of 92 440 arthroscopic procedures, the incidence of VTE was 0.038%.
Our study confirms that shoulder arthroscopy carries a very low risk of VTE. Although all the events occurred in patients without antithrombotic prophylaxis, the incidence of VTE also appeared very low in these groups (0.39%). Thus, our results may be relevant for clinical practice since suggest that thomboprophylaxis may not be required in general patients undergoing shoulder arthroscopy. None of the potential risk factors analyzed in our population seem to be associated with an increased risk of VTE. Patients who developed a VTE during follow-up had a significantly higher age in comparison to patients who did not developed a VTE. Thus, although the absolute risk of VTE is low in this subgroup of patients and this incidence did not significantly differ to the incidence of VTE in younger patients, the use of antithrombotic prophylaxis should be evaluated on a case-by-case basis in this subgroup.
Our study has some potential limitations. First, we included only symptomatic events. However, the clinical meaning of asymptomatic ultrasound detected DVT remains to be established. Second, due to the low number of venous thromboembolic events, we were not able to evaluate the role of other potential risk factors such as cancer and previous VTE. Thus, results of our study may not be applicable to patients with these concomitant risk factors.
In conclusion, results of our large registry suggest that the rate of symptomatic VTE in patients undergoing shoulder arthroscopy is low. Thus, thromboprophylaxis does not appear to be mandatory in this setting. Other studies are warranted to specifically evaluate the safety and efficacy of antithrombotic prophylaxis in older patients and in patients with other concomitant risk factors for VTE.
Footnotes
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The Italian RECOS Registry was supported by an unrestricted educational grant from Bayer-Schering; the pharmaceutical company had no role in analyzing the data or preparing the manuscript.