Outcomes
The main patient outcomes that were evaluated were efficacy of therapy
(measured by complete thrombus resolution following diagnostic
intervention and a course of anticoagulation), and safety (measured by
bleeding events following the procedure). For patients who had serial
follow up images available for review, the 6-month follow up image (or
closest available to 6 months after diagnosis) was the time point
selected. If follow up imaging was not performed at 6 months or later,
the latest follow up image prior to the 6-month point was used. Severity
of bleeding was classified according to the International Society of
Thrombosis and Haemostasis (ISTH) scale, with major bleeding episodes
defined as fatal bleeding, bleeding with a decrease in hemoglobin of 2
g/dL in a 24-hour period, retroperitoneal bleeding, intracerebral
bleeding, or bleeding that requires surgical intervention in operating
rooms. Non major bleeding events include documented bleeding that did
not meet criteria for a major bleeding episode (referred to as
clinically relevant non-major and minor bleeding in the ISTH
scale).19 As many of the interventional technologies
employed are red blood cell depletive without leading to actual
bleeding, post-interventional declines in hemoglobin that were noted
without an identified bleeding event were not counted as bleeding
adverse events.
The major outcomes were evaluated within the two thrombolysis groups;
CDT and “on-table” thrombolysis. Additional secondary outcomes
included thrombus progression/recurrence and PTS. At the time of
evaluation, our center did not incorporate standard PTS scoring systems
into our follow up records; nonetheless, standard symptoms of PTS were
recorded, including extremity swelling, pain, redness, fullness,
decreased range of motion, heaviness, and presence of ulcers. Review of
symptoms for PTS were delayed until the acute phase of the DVT has
passed, at 6 months following diagnosis.20