Penile Sensory Changes After Plaque Incision and Grafting Surgery for Peyronie’s Disease
Jean E. Terrier, MD; Raanan Tal, MD, FECSM; Christian J. Nelson, PhD; John P. Mulhall, MD, MSC, FECSM, FACS
FIRST PUBLISHED: September 5, 2018 – The Journal of Sexual Medicine
Surgical procedures are considered the gold standard for correcting deformities caused by Peyronie’s disease. One option, plaque incision and grafting (PIG) is usually reserved for men with severe curvature, complex deformities, and/or an hourglass deformity.
PIG procedures do have complications, with postoperative rates of penile sensation loss ranging from 0% to 20%.
This study aimed to define the rate and chronology of penile sensation loss in men who have undergone PIG. It also investigated predictors of sensory loss in these patients.
The study group included 63 men who underwent PIG to correct dorsal or lateral deformity and had at least 6 months of follow-up data. Assessments of penile sensation and curvature were made before surgery and again postoperatively at 1-week, 1-month, 6-month, and 1-year follow-up points.
After an erection was induced by intracavernosal injection, curvature was measured with a goniometer.
Penile Sensation Assessment
A biothesiometer was used to measure vibratory sensation thresholds. Two cycles in “ascending—descending order” were conducted for each participant.
• The ascending phase started with the lowest level of stimulation, which was gradually increased until sensation was perceived.
• The descending phase started two levels higher than the threshold determined by the ascending phase. Stimulation was then gradually reduced until it was no longer perceived.
The overall threshold was calculated by averaging the two measurements. A reading of ≤7 volts was considered normal sensitivity.
Sensations were measured in six locations:
• Penile dorsal base
• Middle of the dorsal penile shaft
• Corona of the glans
• Middle of the glans
• Penile ventral vase.
Men also reported their penile sensation with a visual analog scale from 0 (numbness) to 10 (perfect sensation).
Sensation loss was described as follows:
• Extensive – any one area greater than 5 cm
• Major – any one area of 2 to 5 cm
• Minor – any one area less than 2 cm
Sensation loss distribution was categorized as focal (limited to one site) or diffuse (existing in more than one site).
One surgeon performed all procedures between 2004 and 2010. Most grafting was done with cadaveric pericardium, although some patients received intestinal submucosa or dorsal/saphenous vein.
One week after surgery, the men began three months of penile rehabilitation, consisting of the use of a phosphodiesterase type 5 inhibitor and traction therapy.
The mean age of the 63 patients was 56 years. At the time of PIG, the men had had Peyronie’s disease for an average of 15 months. Seventy-five percent had a curvature alone, and 25% had associated hourglass/indentation deformities. The average surgery duration was 3.5 hours. Eighty percent of the men had both preoperative and postoperative biothesiometry.
The following table shows the percentage of men with penile sensation loss at the postoperative follow up points:
|Time period||% of men with sensation loss|
|1 week after surgery||21%|
|1 month after surgery||21%|
|6 months after surgery||8%|
|12 months after surgery||3%|
One patient still had extensive sensation loss two years after surgery.
For the whole group, the median biothesiometry scores were 7 volts or below for the entire follow up period. However, scores for men with sensation loss were above 7 volts.
Twenty patients had a significant decrease in erectile rigidity after surgery.
An operation duration of greater than four hours was the only predictor of sensation loss at the 6-month point. No correlations were found with patient age, presence of diabetes, or duration of Peyronie’s disease.
The study adds to experts’ understanding of penile sensation after PIG procedures.
Before surgery, patients should know that sensation loss is possible and that most men regain sensation within a year.
Several limitations were acknowledged:
• Biothesiometry does not provide a complete assessment of sensation loss. However, its simplicity and low cost made it the more practical method.
• The 7 volt cutoff might misclassify older or diabetic patients who might not be able to detect early reductions in sensation thresholds.
• The number of participants was small, and there was no control group.
• Twenty percent of the patients did not have biosthesiometry before their surgery. (The remaining 80% had assessments both before and after surgery.)
“Sensation loss is not uncommon after PIG surgery. It decreases in frequency and severity with time, with only rare cases occurring >12 months. Longer operations appear to be more likely associated with sensation loss.”