Lumbar punctures (LPs) are a common medical procedure that is used to collect cerebrospinal fluid (CSF) to diagnose and manage neurological illnesses. Here, we delve into the results of a new study on the safety of LPs for patients undergoing treatment with thienopyridines.
Lumbar Punctures and Thienopyridines
Lumbar puncture is a relatively safe medical procedure. But one of its rare yet major complications is spinal hematoma with serious outcomes, such as cauda equina syndrome (CES) or myelopathy. The absence of speedy medical intervention with an epidural hematoma may lead to incontinence, irreversible paralysis, and death.
In certain cases, patients undergoing LP have been taking thienopyridines, antiplatelet agents, or adenosine-diphosphate receptor antagonists (ADPra). These drugs include clopidogrel, prasugrel, and ticagrelor.
Patients may have been taking aspirin with these drugs, dual-antiplatelet thrapy, that increases the risk of an epidural hematoma even more. Thienopyridines and aspirin both inhibit the platelet aggregation function, which increases the chances of bleeding after invasive medical procedures.
Despite growing evidence pointing to the safety of LP for patients taking aspirin, there is limited evidence about this procedure’s safety for people taking thienopyridines.
The Study on LP Safety for Patients Taking Thienopyridines
A recent 2023 study explored the medical safety of Lumbar Puncture for patients already undergoing treatment with thienopyridines. The researchers studied 159 retrospective cases from 2014 to 2021 during which a medical facility performed LP without discontinuing ADPra.
Out of the 159 cases (group 1), 116 LP procedures were performed without interrupting ADPRa treatment. The remaining 43 cases also had a median delay of only two days between the time when ADPRa treatment was halted and when the LP procedure was performed. Note that during the LP, 81 patients underwent dual antiplatelet therapy with aspirin and ADPra.
None of the patients suffered complications of a spinal hematoma or other neurological deficits.
The researchers also assessed the medical records of 159 people who opted for LP while taking aspirin (group 2) and without ADPRa (group 3) for comparison. In group 3, only one person experienced back pain at the puncture site along with post-procedure headaches. No other groups documented any side effects.
Results of the Study
The study showed that performing Lumbar Puncture under ADPra or even dual antiplatelet therapy is safe and has no major complications. In fact, discontinuing antiplatelet therapy a week before the procedure may lead to thrombosis of arteries for which dual antiplatelet therapy has been prescribed (e.g., coronary stent thrombosis or recurrent stroke/TIA.
The absence of antiplatelet therapy may also aggravate the risk of cardiovascular morbidities among patients with pre-existing cardiovascular disease.
Furthermore, a previous 2006 study revealed a minimum incidence of late angiographic stent thrombosis (LAST) among 0.35% of patients. It was due to discontinuing clopidogrel or antiplatelet therapy and continuing treatment with only aspirin.
There are also other studies that did not report any risk from performing LP under ADPra. A retrospective study of 100 patients who underwent LP without stopping dual antiplatelet treatment found no major neurological complications even three months after the procedure.
The researchers of the latest study in 2023 also reviewed various publications that reported complications of LP under ADPra or dual antiplatelet therapy. Only three out of the 428 published cases reported spinal hematoma.
Two out of those three cases had alternative explanations for these results, including concomitantly taking diclofenac and repeated attempts to access the intrathecal space. The third case reported mild spinal hematoma and did not need any intervention.
Moreover, only one out of 168 published cases of LP under ADPra monotherapy reported spinal hematoma due to spinal anesthesia under ticlopidine. Ticlopidine is an ADPra that is rarely prescribed. Also, in rare cases, LP under aspirin can lead to spinal hematoma although aspirin is not contraindicated before an LP procedure.
The risk of bleeding and quantitative bleeding time for patients undergoing dual antiplatelet therapy is also greater than antiplatelet monotherapy. So, for people on dual antiplatelet therapy undergoing LP, healthcare professionals must individually weigh the risk of thrombosis and delays in diagnosis against the least risk of periprocedural bleeding.
Considerations for Performing LP With Dual Antiplatelet Therapy
Keeping the minimal risk of spinal hematoma in mind, we must not treat dual antiplatelet therapy as an absolute contraindication for LP. The following elements must be considered before performing LP without stopping dual antiplatelet therapy:
- The indication’s strength and urgency
- Sensitivity, availability, and specificity of different methods to achieve a diagnosis
- The individual risk of thrombotic complications, including acute coronary syndrome, recent ischemic stroke, or cardiac stenting
These factors will give healthcare professionals a better idea of whether or not they should proceed with the LP procedure for a particular patient.
Limitations of the Study
The study of Lumbar Puncture safety for patients undergoing treatment with thienopyridines has a few limitations. First, complications were pulled from old medical records. Although we cannot rule out the partial documentation of complications, we can safely say that adverse outcomes like spinal hematoma may not have been excluded.
The second limitation is the brief follow-up, which is restricted to the period of hospital admission. Nonetheless, spinal hematoma typically develops soon after the procedure. So, it isn’t likely that this complication was not reported owing to the short follow-up.
It is possible to safely perform lumbar punctures without discontinuing thienopyridines for a week. Despite current guidelines and the limitations of the study, further research into this practice may justify a change in the guidelines in the future and prevent diagnostic delays for neurological emergencies.
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