Which patient characteristics predict improvement with vacuum therapy for Peyronie’s disease (plaque size, calcification, curvature angle)?

1. The evidence landscape: promising signals, uneven data

Multiple retrospective cohorts and a few randomized or comparative trials report that VED can reduce curvature or at least stabilize disease, with mean curvature improvements reported in the range of roughly 10–23 degrees in different studies ^{[3] [2] [1]}. Yet many datasets are small, employ varying device protocols (duration, frequency, adjuncts such as rings, shockwave or PDE5 inhibitors), and differ in inclusion criteria (acute vs stable phase), which makes pooled conclusions about predictors fragile ^{[3] [7] [8]}.

2. Plaque size: some studies favor smaller plaques, but not universally

A couple of clinical series report that patients with plaque lengths under about 2 cm had higher success rates with vacuum pumping, and plaque reduction correlated with smaller baseline plaque burden in one study ^{[4] [8]}. Conversely, a notable cohort analysis found that baseline characteristics, including plaque metrics, were not significantly different between those who improved and those who did not ^[3]. Thus, smaller plaque size appears plausible as a positive predictor in some datasets but is not a consistently validated, universal marker across the literature ^{[4] [3]}.

3. Plaque calcification: biologic plausibility but limited direct evidence

Mechanistically, calcified plaques are less likely to be mechanically remodeled by traction or negative pressure, and traction-device literature suggests non-calcified plaques respond better to mechanical therapies ^[9]. However, direct, consistent evidence specifically linking VED outcomes to calcification status is sparse in the VED-specific studies cited here; some reviews note lack of benefit when plaques are heavily calcified for other non-surgical therapies, implying a likely reduced VED response but not proving it ^{[9] [6]}.

4. Curvature angle: milder curvature often reported to have better outcomes, but exceptions exist

Several reports and a dedicated study of modified vacuum therapy found higher success rates when baseline curvature was below thresholds like 45°, suggesting milder angulation predicts better mechanical correction ^[4]. Other cohorts, however, report improvement across a broad range of starting angles and did not identify curvature angle as a statistically significant differentiator ^{[3] [2]}. In short, lower baseline curvature is a reasonable clinical predictor in some series but not an absolute rule.

5. Other recurrent predictors: age, timing, and adjunctive therapies

Beyond plaque size, calcification, and angle, several studies flagged younger age and shorter time from symptom onset to presentation as predictors of improvement (time-to-presentation ≤6 months, and per-decade younger age showing higher odds in one analysis), and concurrent use of PDE5 inhibitors appeared beneficial in pooled reviews ^{[5] [6]}. These factors likely reflect greater tissue plasticity and earlier disease amenable to remodeling ^{[5] [6]}.

6. Limitations, conflicts, and practical takeaways

The strongest constraint is heterogeneity: small sample sizes, retrospective designs, mixed adjuncts (ESWT, traction, PDE5i), variable VED regimens, and few head-to-head trials, meaning any predictor is provisional ^{[3] [7] [8]}. Industry or device-preference bias exists in the literature favoring traction devices overall, which could shape emphasis away from null VED findings ^[10]. Practically, evidence supports offering VED as a low-risk, noninvasive option to many patients; those with smaller, non-calcified plaques and milder curvature—especially when younger and seen early—may have a higher chance of measurable improvement, but absence of these features does not guarantee failure given inconsistent findings across studies ^{[4] [9] [3]}.