The value of air plethysmography in predicting clinical outcome after surgical treatment of chronic venous insufficiency

Purpose: The role of air plethysmography (APG) as a predictor of clinical o utcome after surgery in venous disease is yet to be defined. The purpose of this study was to investigate the value of APG in predicting clinical outc ome after venous surgery for chronic venous insufficiency (CVI). Methods: Seventy-three extremities in 71 patients with Class 3 through 6 CV I were assessed preoperatively with CEAP (clinical, etiologic, anatomic, pa thophysiologic) criteria, standing reflux duplex ultrasound scan, and APG w ith measurements of preoperative venous filling index (VFI), venous volumes , ejection fraction, and residual volume fraction. After surgical treatment of the affected limbs, repeat APG studies were obtained within 6 weeks. Es tablished venous reporting standards were used for followup to calculate cl inical symptom scores (CSSs) in each patient. Results: Superficial venous reflux occurred alone in 24 limbs or in conjunc tion with perforator incompetence in 26 limbs. Deep and superficial reflux, with or without perforator incompetence, was found in 16 limbs, and seven limbs had isolated deep insufficiency Follow-up was available in 60 of 71 p atients (mean period, 44.3 months). Postoperative APG demonstrated signific ant hemodynamic changes after surgery as measured with VFI, venous volumes, ejection fraction, and residual volume fraction. Mean CSSs decreased from 7.35 +/- 0.56 preoperatively to 1.79 +/- 0.32 at late follow-up after surge ry (P <.001). With the use of logistic regression, the parameter correlatin g most closely with clinical outcome was the VFI. A normal postoperative VF I (<less than or equal to> 2 mL/s) predictcd a good clinical outcome (CSS l ess than or equal to 2) in follow-up patients, with a positive predictive v alue of 94%, a specificity of 89%, and a sensitivity of 70%. Conclusions: Normalization of the VFI after venous surgery for CVI is predi ctive of a good clinical outcome. This APG measurement may be a useful para meter to predict adequacy of surgery in patients with venous insufficiency.