Routine surveillance detects DVT in neurosurgery patients
MedWire News: Routine surveillance ultrasound has shown that around one in 10 neurosurgery patients receiving dual modality prophylaxis have proximal and/or distal lower extremity deep vein thrombosis (DVT).
"The optimal method of thromboprophylaxis and the value of screening ultrasonography for detection of DVT in neurosurgery patients remains unclear," remark Patricia Henwood (Brigham and Women's Hospital, Boston, Massachusetts, USA) and colleagues.
This is because incidentally discovered asymptomatic thromboses are less likely to propagate or embolize, and that aggressive treatment in a high bleeding-risk population - such as neurosurgery patients - may provide more harm than benefit, they add.
Henwood and team conducted a retrospective review of 7298 ultrasound studies carried out on 2593 neurosurgical patients over 4 years, to determine the incidence of DVT in these patients. According to hospital postsurgical protocol, each patient received twice-weekly surveillance ultrasonography of the lower extremities, in addition to prophylaxis with unfractionated heparin and external pneumatic compression sleeves.
Ultrasonography revealed that 252 (9.7%) patients had proximal and/or distal lower extremity DVT, while 193 (7.4%) had proximal lower extremity DVT alone.
A chart review of 237 of the 252 patients diagnosed with DVT showed that 48.5% were initially admitted for subarachnoid hemorrhage.
The researchers comment that the incidence of proximal DVT they observed is consistent with data published from a number of other studies. They accept that the inability to determine whether the DVT was symptomatic or asymptomatic is a limitation of the study. But, "based on our population and prior studies, we assume the large majority were asymptomatic and detected by the biweekly screening protocol," they remark.
"Depending on the severity of their condition, many neurosurgical patients may not exhibit signs or express symptoms of thrombosis, so surveillance ultrasound may play a unique role in the early detection of DVT and prevention of PE [pulmonary embolism] in this patient population," write Henwood and co-authors in the Journal of Thrombosis and Thrombolysis.
However, "screening ultrasound in neurosurgery patients increases diagnosis of asymptomatic calf vein DVT and furthers the debate on appropriate management of these patients at increased risk for intracranial hemorrhage," they add.
"Hence, it is clear that more large-scale prospective studies are needed to help address this issue," the researchers conclude.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Laura Dean