Pam Harrison

November 11, 2016

Penile prostheses can act as a tissue expander, increasing penile length, and sometimes girth, in men with refractory erectile dysfunction, a retrospective analysis of men undergoing revision surgery suggests.

These findings are "reassuring," said Amr Abdel Raheem, MD, PhD, from the Institute of Urology, University College London Hospitals, United Kingdom.

"Men are often worried about losing some length after surgery, but this study shows that this is not the case," he explained.

The study was presented at the Sexual Medicine Society of North America Fall 2016 Scientific Meeting in Scottsdale, Arizona.

Revision surgery is sometimes performed to change an inflatable implant that has mechanically malfunctioned, and sometimes the patient has decided to change his malleable implant to an inflatable implant.

Men are often counseled preoperatively that there will be some length loss after penile implantation, and a previous study showed that the majority of men experience a decrease of about 0.5 cm after implantation, Dr Raheem reported.

However, "I noticed that whenever I revised an implant, the measurements of the penile corpora were longer, so I ended up putting in a longer implant," he told Medscape Medical News.

"The concept of using prosthetic devices as tissue expanders is well known in plastic surgery, but I wanted to know whether this concept applies to penile implants as well," he explained.

Dr Raheem and his colleagues identified 50 men who had undergone penile revision surgery at their institution over the previous 5 years. Only revisions involving exchange of cylinders were included in the analysis.

Corporal measurements were noted in hospital records, and measurements at the original surgery and at revision surgery were compared.

The mean age at revision surgery was 55 years, and the mean interval between the two surgeries was 4.1 years.

Corporal length increased between original surgery and revision surgery in 39 of the 50 patients (78%). After revision, the mean increase in corporal length was 1.7 cm and the mean increase in cylinder length was 1.6 cm.

"Neither the type nor make of the first implant had an effect on the length gain," Dr Raheem reported.

Patients with penile fibrosis related to Peyronie's disease or postpriapism late insertion achieved a length gain of only 0.8 cm.

Changes in penile girth were noted in a number of men. Ten patients with a malleable implant who underwent revision surgery received a wider malleable implant, two patients with a 9.5 mm malleable implant received a standard inflatable prosthesis, and one patient with a narrow-base inflatable prosthesis received a standard implant.

"This study shows that penile implants act as a tissue expander and may lead to an increase in penile length and girth," said Dr Raheem. He emphasized, however, that he and his colleagues are not suggesting that men with good erections who are concerned about penile length undergo penile implantation.

Dr Raheem pointed out there are types of implants with cylinders that can increase in length over time, so that as the penis grows in length, the cylinders can expand to fill the gap, eliminating the need for revision surgery to replace the implant.

In a previous study of 40 men who received just such an implant — the Coloplast Titan penile prosthesis — three-quarters perceived penile length to be longer or the same as it was prior to surgery (J Sex Med. 2015;12:1298-1304). The investigators used aggressive cylinder sizing and instructed the men to inflate the implant daily for 6 months, then to maximally inflate it for 1 to 2 hours a day for another 6 months.

At the end of 1 year, all but two of the 40 men were satisfied with the overall function and the dimensions of their new implant.

Similarly, another study found that if patients used a vacuum erection device for 10 minutes each day for up to 2 months prior to receiving an inflatable penile prosthesis, cylinder length could be maximized (Adv Sex Med. 2013;3:14-18). Cylinders were left partially inflated during the postoperative period, but after recovery, the men were instructed to inflate the device daily for 3 months.

This approach virtually eliminated patient complaints about reduced penile length after implantation.

"Most of the time we tell the patient that he will lose a centimeter or two of what he had when he was young and had a natural erection," said Steven Wilson, MD, a penile implantation pioneer now in private practice in La Quinta, California.

"If a patient religiously pumps the implant for an hour or so a day, he will at least get his old length back, and perhaps a little bit more," he told Medscape Medical News.

Dr Raheem has disclosed no relevant financial relationships. Dr Wilson serves as a consultant to Abeon, AMA, Coloplast, Neotract, and Sontec.

Sexual Medicine Society of North America (SMSNA) Fall 2016 Scientific Meeting: Abstract 206. Presented November 5, 2016.


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