Photoplethysmography and calf muscle pump function after subfascial endoscopic perforator ligation

Objective: Subfascial endoscopic perforator surgery (SEPS) results in acceptable healing and recurrence rates. The role of hemodynamic venous testing in this situation, however, is poorly understood and inconsistently used. Our ongoing experience was reviewed to explore how SEPS affects the photoplethysmographic assessment of the leg. Methods: Preoperative and postoperative venous refill times (VKTs) were measured with photoplethysmography in 30 limbs in 28 patients who underwent SEPS and superficial ablation, when indicated, with complete clearing of the anterolateral surface of the tibia, thus opening the deep posterior compartment from mid calf to close to the malleolus. Postoperative healing and duplex scanning were used to assess clinical and anatomic success, respectively. The VRTs were classified as 'interpretable' if the leg emptied or 'uninterpretable' if the calf could not empty. The 'interpretable' study results were further classified as 'normal' if the refill took 20 seconds or more or 'abnormal' if less. Results: Before the patients underwent SEPS, six study results (20%) showed inability of the calf to empty and thus were judged uninterpretable. After the patients underwent SEPS, 12 study results (40%) were uninterpretable (NS; P = .09 with the χ² test), of the 24 preoperative interpretable study results, two (8%) were normal, and of the 18 postoperative interpretable study results, seven (39%) were normal (P < .03). With the consideration of only interpretable study results, the mean VRT increased slightly from 12.0 ± 5.1 seconds (mean ± standard deviation) to 14.3 ± 8.1 seconds (NS). Seventeen of 19 ulcers (89%) had healed at a mean follow-up period of 8.6 ± 4.8 months. Conclusion: Although VRT is unpredictably affected by SEPS, the most consistent finding is the inability of the calf to empty, which invalidates the remainder of the test. In addition, most ulcers heal, even with uninterpretable or abnormal postoperative VRTs. This suggests that photoplethysmography is a poor method of assessment of venous reflux after SEPS.