Table 1

Studies assessing pulmonary embolism (PE) rates in patients with untreated IDDVT

Author/yearPopulationSample sizeDiagnostic methodFollow-upPE rate
Lagerstedt et al (1985)40Symptomatic medical patients28Isotopic uptake confirmed by ascending phlebography90 days1/28 (3.6%)
Solis et al (1992)41Inpatient combination of postoperative hip and knee arthroplasty patients. Physician led follow-up28Ascending venography with follow-up CUSUnclarified0/28 (0%)
Pellegrini et al (1993)42Postoperative hip arthroplasty patients nested within prophylaxis RCT24Blinded contrast venogram33 days (22 to 52)4/24 (16.7%)
Oishi et al (1994)43Asymptomatic postoperative THR/TKR patients41CUS6 months0/41 (0%)
Masuda et al (1998)44Retrospective outpatient cohort managed by attending physician26CUS6 months0/26 (0%)
Schwarz et al (2001)45Low-risk ambulatory patients with isolated calf muscle thrombus32CUS3 months0/32 (0%)
Labropoulos et al (2002)46Symptomatic medical and surgical inpatients and outpatients29CUS7 (up to 11) months1/29 (3.4%)
Dorr et al (2007)47Postoperative hip and knee arthroplasty patients nested within prophylaxis RCT25Single CUS at 24 h postoperatively6 months0/25 (0%)
Lautz et al (2009)48Retrospective cohort of inpatients and outpatients with ICMVT who received at least one follow-up CUS406CUS7.5 (up to 11) months7/119 (5.9%)
Schwarz et al (2010)38Low-risk ambulatory patients with isolated calf muscle thrombus53CUS3 months0/53 (0%)
Palareti et al (2010)37Symptomatic outpatients with confirmed IDDVT65CUS3 months1/64 (1.6%)
Horner et al (2014)36Symptomatic ambulatory emergency department patients35CUS3 months1/35 (2.9%)
  • Data are presented as mean (SD), median (IQR) or n/N (percentage) as seen. Diagnostic method refers to original method of diagnosis for IDDVT. Acute PE was confirmed by either V/Q or CTPA testing. Variable follow-up periods are reported as median with upper limit.

  • CTPA, CT pulmonary angiogram; CUS, compression ultrasound; ICMVT, isolated calf muscle vein thrombosis; IDDVT, isolated distal (calf) deep vein thrombosis; RCT, randomised controlled trial; THR, total hip replacement; TKR, total knee replacement; V/Q, ventilation/perfusion.