Outcomes and patient satisfaction after Penuma silicone implant surgery via two surgical approaches

Abstract

Background:

The Penuma is a soft silicone penile implant designed for cosmetic enhancement of the flaccid penis in men who have normal erections.

Objectives:

The goal of this study is to report outcomes on patient satisfaction at least 6 months after Penuma subcutaneous penile implant for cosmetic enhancement of the penis, and to determine if modifications in surgical approach resulted in reduction in postoperative complications.

Design:

Penile measurements, adverse events, and patient satisfaction were compared between patients undergoing the new lateral scrotal incision versus the traditional infrapubic approach.

Methods:

A retrospective chart review was performed on all patients who underwent a Penuma implant by a single surgeon from April 2019 to December 2022. A 26-item non-validated device-specific questionnaire was sent to patients at least 6 months after the date of their initial surgery.

Results:

A total of 92 cases were performed by a single surgeon. The average increase in flaccid length was 2.5 cm (±2.2), representing a 44% increase (p < 0.01). The average increase in girth was 3.1 cm (±1.8 cm), a 32% change (p < 0.01). Seroma requiring drainage occurred in 12%. 7% of patients required operative revision of the implant. When assessed by surgical approach, the revision rate was significantly higher in infrapubic patients (13% vs 2%, p < 0.05). The implant removal rate was also significantly higher when the infrapubic approach was used (21% vs 6%, p < 0.05). 82% of patients reported being satisfied or very satisfied with their postoperative penile appearance. 75% of patients would undergo surgery again.

Conclusion:

The subcutaneous Penuma penile implant appears to improve satisfaction with regard to the appearance of the penis and is a viable option for men who desire to enhance flaccid penile length and girth. Furthermore, the lateral scrotal surgical approach appears to have a lower postoperative complication rate.

Introduction

The Penuma^® (International Medical Devices, Beverly Hills, CA, USA) is a soft silicone penile implant designed for cosmetic enhancement of the flaccid penis in men who have normal erections. The device received 510K clearance by the FDA for this purpose in May 2022. Placement of the implant was first described in 2014. ¹ The ability to enhance the size and the appearance of the penis is something frequently desired by patients; up to 45% of men desire a larger penis. ² Previously published data have demonstrated an average increased mid-shaft girth of 56.7%, or 3.0 cm, with the Penuma implant, which also increases the flaccid length of the penis. ³

The primary adverse events (AEs) associated with the Penuma are seroma, infection, and scar formation. ³ Less frequent complications include erosion, change in penile sensation, flaring of the device, proximal or distal dislodgement, and failure to satisfy the patient’s cosmetic goals. The Penuma is an elective, purely cosmetic surgery, and there is currently only a small cohort of surgeons in the United States (US) performing this operation. The infrapubic incision was initially utilized to intussuscept the penis for subcutaneous insertion of the Penuma since its introduction, but implanting surgeons have recently adopted a lateral scrotal incision. ³ We examine a prospective analysis of outcomes and AE rates of a single surgeon’s Penuma implants, paying particular attention to surgical approach and how it affected AEs. We also created a non-validated device specific survey to analyze patient perspectives after the surgery regarding the size and appearance of their penis, sexual relationship, self-esteem, and overall satisfaction. The primary goal of this study was to provide some of the first reported outcomes with respect to early patient satisfaction, and to determine if modifications in technique resulted in a reduction in postoperative complications.

Methods

This study received Institutional Review Board approval from the Advarra IRB. The reporting of this study conforms to the Strengthening the Reporting of Observational Studies in Epidemiology statement: guidelines for reporting observational studies. ⁴ Inclusion criteria included men aged 18–65 with the perception of inadequate penile girth or length. ⁵ Exclusion criteria included men who were not circumcised, stretched penile length (SPL) < 6 cm, prior penile girth enhancement procedure, history of immunosuppression, anti-coagulation that could not be stopped, uncontrolled diabetes, erectile dysfunction refractory to oral medication, recurrent or active urinary tract infection, and patients who smoke and were unable or unwilling to stop 2 weeks prior to surgery and for at least 6 weeks after surgery.

Preoperatively, patients were evaluated extensively with a detailed medical history and several validated questionnaires focusing on identifying body dysmorphic disorder, including Penile Dysmorphic Disorder Screener, Beliefs About Penis Size Scale, Body Dysmorphic Disorder Modification of the Yale-Brown Obsessive Compulsive Scale, and the Male Genital Self-Image Scale. Patients with responses indicative of severe penile dysmorphic disorder were evaluated by a licensed sex therapist prior to being considered for surgery. Patients were seen in the office on postoperative day 1 and again on postoperative day 3–4 for drain removal, and were instructed to email pictures of their penis at least every 2 weeks for the first 6 weeks postoperatively, and at least monthly thereafter.

Surgical technique was performed per training by Dr. Elist and has been described in depth previously. ⁶ The patient is prepared with IV antibiotics, a urethral washing with an antibiotic or antiseptic solution, and extensive chlorhexidine scrub followed by ChloraPrep™ (BD, Franklin Lakes, NJ). A pudendal nerve block with 20 ml of 0.5% plain ropivacaine is then performed. The infrapubic approach is begun through a transverse 4–5 cm incision centered over the base of the penis. Dissection is made into the infrapubic space. The plane deep to the dartos muscle is developed down to the root of the penis. The area of the suspensory ligament is developed without violating the ligament. The penis can then be everted through the incision. Dissection is made superficial to Buck’s fascia into the subcoronal sulcus, taking care to leave the fibroareolar tissue intact on the dartos side of the dissection to preserve blood flow to the penile shaft skin. Dissection is performed sharply, and bipolar electrocautery is used only to control bleeding where necessary. The 12 o’clock position on the inner aspect of the subcoronal sulcus is identified with a tonsil clamp and confirmed to remain at the 12 o’clock position when the penis is reverted back to its normal anatomic position. The device is prepared, and all personnel change their outer gloves. The distal lateral edges are trimmed as needed and the device is dipped in the irrigation solution. It is brought on the field and secured to the subcoronal sulcus tunica albuginea with an interrupted figure-of-eight 3-0 Ethibond™ (Johnson & Johnson MedTech, Warsaw, IN) sutures on either side of the previously marked 12 o’clock position. Confirmation of proper orientation is made, and the device is further secured with interrupted figure of eight 2-0 Ethibond sutures out to the lateral margin of the device. After the device is secured distally, the penis is reinverted back to its normal anatomic position and the proximal end of the Penuma device is placed in the infrapubic space just over the suspensory ligament. The proximal end is trimmed and rounded. Confirmation is made that the device is properly positioned and there is no flaring of the device and it sits symmetrically on the dorsal shaft of the penis. Hemostasis is carefully obtained, and the field is irrigated thoroughly with antibiotic and antiseptic solution. A fully perforated #10 JP drain is placed through a separate stab wound in the inferior aspect of the hemiscrotum and secured to the skin. The incision is closed in three layers. The lateral scrotal approach is performed similarly, through a 4-cm incision on the left or right lateral scrotum and carried down through the skin and dartos muscle.

A retrospective chart review was performed on all patients who underwent Penuma implants with a single surgeon from April 2019 to December 2022. Charts were analyzed for penile measurements, surgical incision, postoperative AE’s, and the need for additional surgery to revise or remove the device. Penile measurements of flaccid dorsal length from base of penis to meatus, stretched dorsal length from pubis to corona, and flaccid mid-shaft penile girth were taken at the preoperative evaluation and on the day of surgery. Postoperative measurements were taken intraoperatively after the device had been placed, and at subsequent postoperative appointments. In patients who had more than one instance of postoperative measurements, the latest measurements were used in analysis, as this was felt to be the most accurate depiction of anticipated long-term results. Erect penile lengths and girths were not measured.

Statistical analysis was performed using SPSS statistical software (IBM SPSS Statistics, Version 26, Armonk, N.Y., USA). A paired t-test was used to compare penile measurements before and after surgical intervention. A Chi-square analysis was performed to compare the complication rate between infrapubic and lateral scrotal approach. Statistical significance was defined as a p value < 0.05. The changes in flaccid penile length and girth as well as SPL were assessed in the complete cohort.

A 26-question non-validated questionnaire was created to assess the patient’s perception of the appearance and feel of their penis as well as sexual satisfaction before and after surgery. The survey was sent via email to all patients that were at least 6 months from surgery and still had the device in place. This time frame was chosen to allow for implant related changes, including feel and sensation, to stabilize. Approximate time to complete the survey was 10 min, and the patients were not compensated for completion of the survey.

Results

Demographics

A total of 92 patients underwent Penuma insertion between April 2019 and December 2022. The mean age at time of surgery was 44 years, with an age range from 21 to 66 years old. 45% of men were married at time of surgery.

Penile size

Flaccid length measured from the dorsal base of the penis to the meatus, SPL measured from the pubis to corona, and flaccid mid-shaft girth were recorded. The mean flaccid penile length preoperatively was 8.2 cm (SD 2.0 cm), the mean SPL was 12.1 cm (SD 1.5 cm), and the mean preoperative flaccid girth was 9.7 cm (SD 1.2 cm). The mean increase in flaccid length was 2.5 cm (SD 1.9), representing a 44% increase (p < 0.01). This did not differ between the lateral scrotal and the infrapubic incision groups (p = 0.2). The mean increase in girth was 3.1 cm (SD 1.3), representing a 32% change (p < 0.01), which also did not differ significantly between surgical approach used (p = 0.09). The mean change in SPL was 0 cm (SD 1.0 cm).

Approach and complications

In our series of 92 total cases, 39 were performed using the infrapubic approach, and 53 using the lateral scrotal approach. Examples of results from both approaches are depicted in Figure 1. Complication rates stratified by surgical approach are described in Table 1. The most common complication following implantation was seroma, which is consistent with what has previously been published,^3,6 11 (12%) patients experienced a seroma requiring drainage under local anesthesia in the office. These seromas formed despite a period of closed suction drainage for up to 3 days postoperatively. The incidence of seroma was not significantly different based on surgical approach. Implant malposition was the most common reason for operative revision in 7% (6) of patients. Of those that underwent revision for malposition, three patients had distal flaring of the device and two patients had proximal dislodgement. One patient underwent a successful repair of a small (3-mm) skin erosion, which preserved his original device. The need for any revision was significantly higher in patients who underwent an infrapubic approach versus the lateral scrotal approach (13% vs 2%, p < 0.05). A total of 11 (12%) of patients had the device removed for reasons including dissatisfaction with achievement of their cosmetic goals (three), erosion (four), and infection (four). The removal rate was higher when the infrapubic approach was used compared to the lateral scrotal approach (21% vs 6%, p < 0.05) (Table 2). Two cases early in our surgical experience were aborted due to distal shaft skin perforation; both patients subsequently had devices successfully placed at a separate encounter.

Figure 1.

Patient prior to undergoing Penuma implant (left) and at 1 year postoperative (right) via the infrapubic approach (top) and left lateral approach (bottom).

Table 1.

Adverse events based on surgical approach.

Type of adverse event	Infrapubic (%)	Lateral scrotal (%)	p Value
Total cases	39	53
Seroma	4 (10%)	7 (6%)	0.690
Revision	5 (13%)	1(2%)	0.034
Removal	8 (21%)	3 (6%)	0.028
Aborted	2 (5%)	0 (0%)	0.093

Table 2.

Reasons for device removal.

Reason	Infrapubic (n = 39)	Lateral scrotal (n = 53)	p Value
Any reason	8 (21%)	3 (6%)	0.03
Failed cosmetic goal	3 (8%)	1 (2%)	0.3
Infection	3 (8%)	0 (0%)	0.01
Erosion	2 (5%)	2 (4%)	1

Patient perception and satisfaction

Patients were asked to rate their feelings with regard to their penis and sexual experience before and after the implant as part of the emailed survey. Despite repeated attempts to contact the patients via e-mail and telephone calls, only 43 (47%) patients completed the survey. Complete survey results are described in Table 3. Of note, 55% stated that they were dissatisfied with their sexual relationship prior to surgery, compared to 18% after the implant. 68% endorsed being dissatisfied or very dissatisfied with the appearance of their penis prior to surgery, compared to 82% who reported being satisfied or very satisfied with their penile appearance after surgery. 63% were satisfied or very satisfied with their ability to climax prior to surgery compared to 71% after surgery. Patients were asked about how natural it was to palpate the penis after Penuma implantation. The majority of patients (56%) were satisfied postoperatively with how natural the penis felt, and 73% were satisfied with how natural the penis looked. Most patients (75%) agreed or somewhat agreed that they would undergo surgery again.

Table 3.

Post-Penuma satisfaction survey results.

Survey questions	Very satisfied (%)	Satisfied (%)	Dissatisfied (%)	Very dissatisfied (%)
Sexual relationship prior to surgery	26%	19	29	26
Sexual relationship after surgery	43	40	10	7
Appearance of penis prior	19	17	21	43
Appearance of penis after	46	39	10	5
Ability to reach orgasm prior	48	17	21	14
Ability to reach orgasm after	43	31	12	14
Emotional closeness during sex prior	26	40	12	21
Emotional closeness during sex after	45	40	13	3
Size of penis prior	7	21	31	40
Size of penis after	43	48	5	5
How natural penis looks after	43	33	19	5
How natural penis feels after	29	31	26	14
Self-confidence with respect to penis prior	7	27	24	41
Self-confidence with respect to penis after	49	37	7	7
Appearance of penis when flaccid	41	27	17	15
Appearance of penis when erect	36	52	10	2
Final outcome of implant surgery	36	36	17	12
Additional survey questions		Agree (%)	Somewhat agree (%)	Disagree (%)
Satisfied with the amount of information given regarding expectations		64	21	14
Implant had no effect on frequency of sexual contact		58	15	28
Feel comfortable touching penis		74	14	12
Would do surgery again		55	21	24
Penis feels natural after surgery		38	36	26
Sexual satisfaction is improved after surgery		49	20	32
Satisfied with appearance of penis		62	26	12

Bold is used to make distinction between the different parameters easier to identify.

Discussion

Cosmetic enhancement surgery, including breast, facial, and buttock augmentation, is increasingly common in American women. ⁷ It is known that quite a few men desire penile enhancement and would pursue it if it were safe and effective. ⁸ Various surgical techniques for penile enhancement have been described, including suspensory ligament release, suprapubic lipectomy, and tissue grafting and flaps; however, data regarding outcomes are limited and generally unfavorable. ⁹ Minimally invasive techniques for penile enhancement, such as hyaluronic and polylactic filler injections, have shown promising results; however, these are limited by their temporary nature and subsequent lack of long-term efficacy. ¹⁰

The Penuma implant offers a permanent surgical implant for men desiring penile enhancement. Due to the elective and novel nature of the procedure, potential patients must be evaluated extensively for both physical and psychological appropriateness for surgery. ¹¹ Given the low number of surgeons who have been trained and initiated performing Penuma implants since 2019, there are minimal data published regarding the safety and outcomes of the implant when performed by physicians other than the inventor of Penuma. There is also a scarcity of data on the patients’ perceptions of the implant postoperatively.

Early published case reports of deformed penises following Penuma surgery attracted media attention. ¹² The explanation for the early troubles was thought to be due to attempts to preserve the Penuma in place when complications appeared. Penuma surgeons now realize that addressing the AE early or removing the prosthesis is best when a less than optimum outcome is apparent. Indicative of this new approach is our series where removal of the device was performed early in the postoperative period for malposition, erosion, infection, or patient dissatisfaction. ¹³

This series suggests that patients are largely pleased with the outcome and do not regret undergoing implant surgery. The average increase in flaccid length was 2.5 cm and average increase in girth was 3.1 cm. Of note, the majority of our patients were measured immediately postoperatively or in the short term (< 3 months), and the inventors of the device have suggested that additional gains in flaccid length can occur over time, likely due to softening of the capsular attachments around the Penuma. ³ Overall, 75% of our patients who still had the implant in place reported that they would undergo surgery again if given the choice. Our survey demonstrates that the Penuma implant appears to have a positive effect on perceived sexual relationship and self-confidence with regard to the penis. The lower level of patient satisfaction with the “natural” feel of their penis is not unexpected given the relative rigidity of the device necessary to achieve improvement of penile visibility outside the body. ¹¹

Our data on one surgeon’s experience with postoperative complications over the course of 3 years are like what has been previously published.^3,6 Although our seroma rate of 12% is higher than the 5% previously described, ³ all seromas resolved with drainage (1–3 times) in the office with no instances of infection.

Our infection rate was 3%, which is comparable to what has been reported by other centers.^3,6 Of note, the majority of infections occurred at the beginning of the surgeon’s experience, suggesting improvement with the expected learning curve as well as ongoing adaptations to the intraoperative medication protocol. This is also reflected in the change from the infrapubic to lateral scrotal approach, which not only offers an improved cosmetic result but also appears to demonstrate superior clinical safety outcomes. The need for revision due to suboptimal positioning of the device, which in our cohort was for distal flaring and proximal dislodgement, decreased from 12.8% to 1.8% when we transitioned from the infrapubic approach to the lateral scrotal approach (p < 0.05).

Our data did not demonstrate a statistically significant decrease in seroma rates between the two approaches, though the lateral scrotal approach has been associated with a decreased seroma rate in other cohorts. ¹³ Our cohort exhibited an erosion rate of 5%. In most cases of erosion, the device was ultimately removed, though surgical repair with extensive irrigation much like an infected penile prosthesis salvage procedure was successful in one case. Removal in the case of erosion was largely anticipatory, as erosion opened the device to external bacteria, increasing the likelihood for infection. We report an overall 12% explant rate. This was significantly lower after the transition to the concealed lateral scrotal approach. Three of those who ultimately underwent explantation did so because the device failed to satisfy their cosmetic goals despite no identifiable problem with the device. This rate of explant for dissatisfaction suggests room for improvement in setting preoperative expectations. Recently published data suggested that for patients who do opt to have the device removed, a specific program of penile rehabilitation may be beneficial to restore the penis to its original appearance and function. ¹⁴

There are several limitations to this study. It is retrospective in nature, and the prospective survey data are limited by the patients that opted to complete it. Our survey was designed specifically with Penuma patients in mind, but it is not validated. We only had patients complete the survey who were still implanted which we expect will bias results on patient satisfaction. In addition, because the patient surveys were de-identified, we could not assess differences in satisfaction between the infrapubic and lateral scrotal incision groups. The retrospective review for complications is ongoing, though given the novelty of this surgery and our surgeons’ relatively short experience with it, we do not have long-term data at this time. It is thus possible that there are long-term negative outcomes related to the Penuma implant that we did not capture with this study. Furthermore, the Penuma Surgeons Group, the network of implanting physicians, has been actively involved with the manufacturer to make adjustments in the surgical technique. The operative technique and urgency of perioperative interventions have been changed over the course of this study, and though it could not be captured in this study, we believe that these adjustments will result in lower complication rates over time. Currently, the surgeon involved in this study is only using the lateral scrotal incision for implantation, which is both more cosmetically pleasing than the previously used infrapubic incision and appears to result in a reduced overall complication rate. There have also been adjustments in intraoperative medications, including the incorporation of intravenous tranexamic acid preoperatively, and intraoperative irrigation with Irrisept (Chlorhexidene gluconate 0.05%, Irrimax Corp, Lawrenceville, GA, USA), triamcinolone and tranexamic acid. Importantly, the use of bipolar electrocautery has been also significantly limited only to obtain pinpoint hemostasis on the penile shaft and not used at all on the skin or dartos side of the dissection. We believe that this will reduce the likelihood of postoperative seroma formation, tissue swelling, and erosion. Ultimately, given the novelty of the implant surgery and the limited number of surgeons performing the surgery, the operative technique is actively evolving, and we expect that complication rates will continue to decrease as techniques and materials are refined.

Conclusion

The Penuma appears to be a viable option for men who desire to enhance flaccid and erect penile girth as well as flaccid length. Complications, including the need for re-operation, are low but not negligible; patients appear to be satisfied with results of the surgery in the short term. The transition to the lateral scrotal approach from the infrapubic approach appears to offer improved outcomes. Further studies are needed to validate this single surgeon experience.