Table 13.

—[Section 2.11] Summary of Findings: Surgical Thrombectomy vs No Surgical Thrombectomy for Extensive Acute DVT of the Leg^a,144

Outcomes	No. of Participants (Studies), Follow-up	Quality of the Evidence (GRADE)	Relative Effect (95% CI)	Anticipated Absolute Effects
				Risk With No Surgical Thrombectomy	Risk Difference With Surgical Thrombectomy (95% CI)
Mortality not reported	…	…	…	…	…
Nonfatal recurrent VTE	51 (1 study), 3 mo	Lowb,c due to risk of bias and imprecision	RR 0.37 (0.02-8.75)	48 per 1,000d,e	30 fewer per 1,000 (from 47 fewer to 372 more)
Nonfatal major bleeding	51 (1 study), 3 mo	Lowb,c due to risk of bias and imprecision	Not estimable (no events)	…	-
PTS	51 (1 study), 2 y	Lowf,g due to risk of bias and imprecision	RR 0.63 (0.44-0.9)h	588 per 1,000i	218 fewer per 1,000 (from 59 fewer to 329 fewer)j
QOL not measured	…	…	…	…	…

The basis for the assumed risk (eg, the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). Working group grades of evidence are as follow: High quality, further research is very unlikely to change our confidence in the estimate of effect; moderate quality, further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate; low quality, further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; very-low quality, we are very uncertain about the estimate. See Table 1, 3 and 10 legends for expansion of abbreviations.

^aThe study included patients with DVT with symptoms of leg swelling not exceeding 7 d and a proximal extension of the thrombus above the inguinal ligament but not into the vena cava.

^bNot clear whether allocation was concealed. No blinding reported. Not clear whether analysis was intention to treat. Follow-up rate was 88% at 6 mo. Study not stopped early for benefit.

^cCI includes values suggesting either harm or benefit.

^dBaseline risks for nonfatal recurrent VTE derived from Douketis et al.¹⁰⁸

^eOne event was a symptomatic PE.

^fIn addition to other study limitations, this outcome was assessed by those who did the surgery and anticoagulation. No standardized tool was used. One surgical patient had an amputation secondary to venous gangrene and was not counted in the PTS assessment.

^gFew number of events. This warrants rating down the quality of evidence by a second level when considered along with study limitations.

^hThe RR is based on the 6-mo data.

ⁱThis estimate is based on the findings of the VETO study.¹⁰² This probably underestimates PTS baseline risk, given that overall, 52% of patients reported the current use of compression stockings during study follow-up.

^jSevere PTS: assuming the same RR of 0.63 and a baseline risk of 13.8% over 2 y,¹⁰² the absolute reduction is 51 fewer severe PTS per 1,000 (from 14 fewer to 77 fewer) over 2 y.