Current Issue

The online formats of SRGS include access to What You Should Know (WYSK): commentaries on articles published recently in top medical journals. These commentaries, written by practicing surgeons and other medical experts, focus on the strengths and weaknesses of the research, as well as on the articles' contributions in advancing the field of surgery.

Below is a sample of one of the commentaries published in the current edition of WYSK.

Jackson CD, Cifu AS, Burroughs-Ray DC. Antithrombotic Therapy for Venous Thromboembolism. JAMA. 2022;327(21):2141-2142. doi:10.1001/jama.2022.7325
Stevens SM, Woller SC, Kreuziger LB, et al. Antithrombotic Therapy for VTE Disease: Second Update of the CHEST Guideline and Expert Panel Report [published correction appears in Chest. 2022 Jul;162(1):269]. Chest. 2021;160(6):e545-e608. doi:10.1016/j.chest.2021.07.055

Commentary by: Vina Y. Chhaya, MD, MPH; James D. Greenwood, MD; and Melina R. Kibbe, MD, FACS

One of the more vexing postoperative complications for surgeons is venous thromboembolism (VTE), which encompasses deep vein thrombosis (DVT) of the lower extremities as well as pulmonary embolism (PE). Data from the National Surgical Quality Improvement Program (NSQIP) indicates that the annual incidence of postoperative VTE ranges from 0.5% to 1.6%.¹ Mean predicted costs are also 1.5-fold higher for patients developing this complication compared to controls, matched on both surgery type and active cancer status.^2,3 While major trauma and surgery are strong but acute and transient risk factors of VTE, surgical patients often have additional and more chronic risk factors, such as pregnancy, cancer, obesity, chronic inflammatory disorders, or family history that elevate their overall risk of developing a postoperative VTE.⁴ These risk factors, as classified by the International Society on Thrombosis and Haemostasis, contribute to a higher risk of VTE, necessitating extended anticoagulation therapy.^4,5 In response, the American College of Chest Physicians has been publishing the CHEST guidelines to establish a standard of care for the last 40 years. Most recently, the second update to the ninth edition was published.⁶

The format of the second update to the ninth edition still includes evidence tables and pooled data estimates similar to the first update but more transparently details the expert panel's process when examining recent data to update or establish new guidelines. This evidence-to-decision assessment for each clinical question succinctly explains the current data reviewed and how the expert panel decided to change the evidence-based guidelines, if at all, compared to the initial ninth edition and subsequent first update. A highlight of this update is the debut of four new guidance statements reminding us of the complexities of VTE treatment and the importance of the CHEST guidelines in informing standard of care:⁶

In patients with cerebral vein/venous sinus thrombosis, the guidelines recommend anticoagulation therapy for at least the first three months over no anticoagulant therapy. For initial treatment, the guidelines recommend considering low molecular weight heparin (LMWH) and switching to oral anticoagulation if the patient remains stable; otherwise, in patients with progressive neurological deterioration, the guidelines suggest considering thrombectomy versus local thrombolytic infusion with IV heparin (strong recommendation, low-certainty evidence).

In patients with confirmed antiphospholipid syndrome being treated with anticoagulant therapy, the guidelines suggest adjusted dose vitamin K antagonist (VKA) (target INR 2.5) over direct oral anticoagulant (DOAC) therapy during the treatment phase (weak recommendation, low-certainty evidence).

In patients offered extended-phase anticoagulation, the guidelines suggest using reduced-dose apixaban or rivaroxaban over full-dose apixaban or rivaroxaban (weak recommendation, low-certainty evidence). Reduced dose refers to apixaban 2.5 mg twice daily and rivaroxaban 10 mg once daily.

In patients offered extended-phase anticoagulation, the guidelines recommend reduced-dose DOAC over aspirin or no therapy (strong recommendation, low-certainty evidence) and suggest rivaroxaban over aspirin (weak recommendation, moderate-certainty evidence).

In patients with an unprovoked proximal DVT or PE who are stopping anticoagulant therapy and do not have a contraindication to aspirin, the guidelines suggest aspirin over no aspirin to prevent recurrent VTE (weak recommendation, low-certainty evidence).

In addition, this second update to the ninth edition has changed eight of the earlier recommendations, with six of these being more than minor phrasing changes that are important for surgeons to know:

In patients with low-risk PE, the guidelines recommend outpatient treatment over hospitalization, provided access to medications, ability to access outpatient care, and home circumstances are adequate (strong recommendation, low-certainty evidence).

In patients with VTE, the guidelines recommend apixaban, dabigatran, edoxaban, or rivaroxaban over VKA as treatment-phase (first three months) anticoagulant therapy (strong recommendation, moderate-certainty evidence).

In patients with acute VTE in the setting of cancer (cancer-associated thrombosis), the guidelines recommend an oral Xa inhibitor (apixaban, edoxaban, rivaroxaban) over LMWH for the initiation and treatment phases of therapy (strong recommendation, moderate-certainty evidence).

In patients with superficial venous thrombosis (SVT) who are treated with anticoagulation, the guidelines suggest fondaparinux 2.5 mg daily over other anticoagulant treatment regimens such as (prophylactic or therapeutic dose) LMWH (weak recommendation, low-certainty evidence). In patients with SVT who refuse or are unable to use parenteral anticoagulation, the guidelines suggest rivaroxaban 10 mg daily as a reasonable alternative for fondaparinux 2.5 mg daily (weak recommendation, low-certainty evidence).

Guidelines for extended-phase anticoagulant therapy have changed to combine multiple statements of time-limited periods of therapy. Previous statements regarding "treatment of a longer time-limited period (e.g., 6, 12, or 24 months) or extended therapy (no scheduled stop date)" have been changed to "extended-phase anticoagulation." These patients with VTE are also grouped into risk profiles consistent with what is recommended by the International Society on Thrombosis and Haemostasis: major transient risk factor (including surgery), minor transient risk factor, or absence of transient provocation (unprovoked VTE or provoked by persistent risk factor).

In patients offered extended-phase anticoagulation, the guidelines recommend reduced-dose DOAC over aspirin or no therapy (strong recommendation, low-certainty evidence) and suggest rivaroxaban over aspirin (weak recommendation, moderate-certainty evidence).

In patients with acute DVT of the leg, the guidelines recommend anticoagulant therapy alone over interventional (thrombolytic, mechanical, or pharmacomechanical) therapy (weak recommendation, moderate-certainty evidence). The minor rephrasing expands on the interventional therapy, whereas the first update referred to this as catheter-directed thrombolysis.

In patients with acute DVT of the leg, the guidelines recommend against using compression stockings routinely to prevent post-thrombotic syndrome (PTS) (weak recommendation, low-certainty evidence). The word "against" replaces "not" in the first 2016 update.

Arguably, the most significant change brought about by new evidence allows the panel to recommend DOACs over VKAs and LMWH for treatment-phase therapy in the setting of cancer, for which the first update previously recommended LMWH over VKAs (Grade 2B) and DOAC therapy (Grade 2C). For patients with antiphospholipid syndrome, adjusted dose VKAs are recommended over DOACs. Additionally, outpatient treatment with DOACs for acute VTE in patients with a low risk of complications was upgraded to a strong recommendation, aligning with a reduction in hospital costs and patient preferences.

This second update, in particular, incorporates recent studies to support the use of DOACs and aspirin when indicated to treat acute VTE. With more studies demonstrating the efficacy and safety of DOACs, this update increases the grade of the recommendation to treat acute VTE with DOACs (strong) and changes the standard of care for patients with acute VTE in the setting of cancer to recommend DOACs over LMWH. A caveat to this recommendation is that LMWH has a safety advantage over edoxaban and rivaroxaban for cancer-associated thrombosis in patients with luminal GI malignancies. Furthermore, this second update favors using reduced-dose DOACs compared to full-dose therapy and aspirin in patients requiring extended-phase therapy. Aspirin can be used to prevent recurrent VTE for patients who are stopping anticoagulation entirely.

The American College of Chest Physicians continues to review new evidence for inclusion and publishes updates to the CHEST guidelines that inform the standard of care for acute VTE, but there are notable limitations that set the stage for future studies. Specifically, the evidence for the treatment of isolated subsegmental PE is entirely from retrospective studies and lacks support from high-quality prospective data. Studies examining the treatment of acute PE often enroll only symptomatic patients; therefore, we lack evidence on the management of incidentally diagnosed asymptomatic acute PE. More importantly, for surgeons who might be called upon to perform catheter-directed thrombolysis, only small randomized trials support this intervention with caveats depending upon a patient's bleeding risk. Thus, while catheter-directed thrombolysis is mentioned in the guidelines, it is not recommended because of higher-quality evidence supporting systemic thrombolytic therapy. Noting the paucity of data under specific treatment guidelines enables us to design the necessary studies and continue working towards the collective goal of the CHEST guidelines: determining and disseminating evidence-based standards of care for treating acute VTE.

As surgeons, we introduce a major, acute, and transient risk factor for the development of VTE in our patients. It follows that we should be equipped to treat not only our technical postoperative complications but also any associated complications. While our healthcare system continues to adjust to the burdens introduced by the COVID-19 pandemic, we are dealing with immediate staff shortages and projected shortages in primary care and general surgery. A recent report from the Association of American Medical Colleges projects a shortage of up to 48,000 primary care physicians and up to 30,200 surgical specialists by 2034.⁷ With increasing barriers to accessing care resulting in patients who are lost to follow-up or even unable to establish care, surgeons are poised to reduce morbidity and mortality by providing comprehensive care to our patients who present with acute VTE. Understanding the CHEST guidelines and this second update enables us to be self-sufficient in managing acute VTE and avoids unnecessary referrals for managing anticoagulant therapy.

References

1. Henke PK, Kahn SR, Pannucci CJ, et al. Call to Action to Prevent Venous Thromboembolism in Hospitalized Patients: A Policy Statement From the American Heart Association [published correction appears in Circulation. 2020 Jun 16;141(24):e932] [published correction appears in Circulation. 2021 Feb 16;143(7):e249]. Circulation. 2020;141(24):e914-e931. doi:10.1161/CIR.0000000000000769
2. Cohoon KP, Leibson CL, Ransom JE, et al. Direct medical costs attributable to venous thromboembolism among persons hospitalized for major operation: a population-based longitudinal study [published correction appears in Surgery. 2015 Nov;158(5):1451]. Surgery. 2015;157(3):423-431. doi:10.1016/j.surg.2014.10.005
3. Dobaria Bs V, Hadaya J, Ebrihiminan S, Verma A, Sanaiha Y, Benharash P. Impact of Venous Thromboembolism on Readmissions and Resource Use Following Emergency General Surgery. Am Surg. 2022;88(10):2436-2439. doi:10.1177/00031348221101478
4. Khan F, Tritschler T, Kahn SR, Rodger MA. Venous thromboembolism. Lancet. 2021;398(10294):64-77. doi:10.1016/S0140-6736(20)32658-1
5. Kearon C, Ageno W, Cannegieter SC, et al. Categorization of patients as having provoked or unprovoked venous thromboembolism: guidance from the SSC of ISTH. J Thromb Haemost. 2016;14(7):1480-1483. doi:10.1111/jth.13336
6. Stevens SM, Woller SC, Kreuziger LB, et al. Antithrombotic Therapy for VTE Disease: Second Update of the CHEST Guideline and Expert Panel Report [published correction appears in Chest. 2022 Jul;162(1):269]. Chest. 2021;160(6):e545-e608. doi:10.1016/j.chest.2021.07.055
7. Association of Medical Colleges. The complexities of physician supply and demand: projections from 2019 To 2034. June 2021. https://www.aamc.org/media/54681/download

The SRGS Recommended Reading List is a summary of the most pertinent articles cited in each issue; the editor has carefully selected a group of current, classic, and seminal articles for further study in certain formats of SRGS. The citations below are linked to their abstracts on PubMed, and free full texts are available where indicated.

SRGS has obtained permission from journal publishers to reprint these articles. Copying and distributing these reprints is a violation of our licensing agreement with these publishers and is strictly prohibited.

Daza JF, Bartoszko J, Van Klei W, Ladha K, McCluskey S, Wijeysundera DN. Improved Re-estimation of Perioperative Cardiac Risk Using the Surgical Apgar Score: A Retrospective Cohort Study. Ann Surg. Jul 8 2022;doi:10.1097/SLA.0000000000005509

The authors reported data from a retrospective cohort study (N=16,835) of patients undergoing noncardiac surgery at a single institution. The study aimed to determine the value of combining a preoperative risk score (Revised Cardiac Risk Index) with a score determined from intraoperative variables (Surgical APGAR Score). The outcome of interest was acute postoperative myocardial injury. The data analysis showed that combining the two scores improved risk assessment significantly.

Raimondi N, Vial MR, Calleja J, et al. Evidence-based guidelines for the use of tracheostomy in critically ill patients. J Crit Care. Apr 2017;38:304-318. doi:10.1016/j.jcrc.2016.10.009

This article reviewed the available evidence and, using an expert consensus panel developed a set of guidelines for the use of bronchoscopy and tracheostomy in patients requiring ventilator support. The guidelines provided advice but not specific recommendations for early versus late tracheostomy.

Kirkilesis G, Kakkos SK, Bicknell C, Salim S, Kakavia K. Treatment of distal deep vein thrombosis. Cochrane Database Syst Rev. 2020;4(4):CD013422. Published 2020 Apr 9. doi:10.1002/14651858.CD013422.pub2

This article provided useful data regarding the use of "deresuscitation" (treatment of fluid overload with diuretics and/or renal replacement therapy) for critically ill patients with signs of significant fluid overload. Using this approach was associated with a significant reduction in short-term mortality risk.