Human Acellular Dermal Matrix Augmentation Phalloplasty Surgery

Abstract

Introduction and Objective:

Many men often have the need to enlarge their penises for psychological gain and to satisfy or to impress their partners. Many surgical techniques have been reported. However, none is the gold standard.

Aim:

To evaluate the efficacy and safety of human acellular dermal matrix allograft in augmentation phalloplasty technique.

Methods:

From March 2015 to September 2017, a total of 182 patients were prospectively recruited into our cohort after complete physical and psychological evaluation that deemed suitable for penile enhancement. Penis circumference was measured at the mid-length of the penis. Mean was 7.03 cm (6.93 ± 1.00 cm) and 12.1 cm (10.59 ± 1.15 cm) during flaccid and erection, respectively. All patients received human acellular dermal matrix graft under spinal or local anesthesia. The allograft was preconditioned in normal saline for 20 minutes, and mesh incisions were made to optimize blood flow. The width was equal to the circumference of both corpus cavernosa but without corpus spongiosum. The length of the graft was determined by measuring the length between the tip of the coronary sulcus and the root of penis. A complete incision below the coronary sulcus to the depth of the Buck’s fascia was made. Then separate the dartos fascia from the Buck’s fascia. The prepared graft was then placed on top of the Buck’s fascia, with the blood-remained side facing the Buck’s fascia. The graft was sutured using 4-0 absorbable polyglycolic acid suture to the Buck’s fascia. Extra caution needed to be taken when fixing ventrally to avoid injuring the urethra. Once completed, the dartos fascia was restored, the dartos fascia and subcutaneous tissue were sutured with 4-0 absorbable suture, and skin closure is achieved subsequently.

Results:

The post-operative course was without complications. At the follow-up after 1 year, the mean flaccid girth increased to 8.07 ± 1.06 cm (P < .05), while the mean erect girth increased to 12.79 ± 1.23 cm (P < .05). Sexual activity was allowed after 8 weeks of surgery. The majority reported that sexual self-esteem and functioning significantly improved. In addition, 59 patients reported alleviation of premature ejaculation.

Conclusions:

Compared to autologous dermis-fat graft and xenograft, augmentation phalloplasty using human acellular dermal matrix has several advantages: (1) it avoids harm harvesting site of the autograft; (2) the effects of dermis allograft can last at least 1 year; and (3) acellular dermal matrix is more likely to be accepted by people.

Introduction

Many men often have the need to enlarge their penises for psychological gain and to satisfy/impress their partners. Across different cultures, a surprisingly unanimous conception of penile size and masculinity exists. Indian Sadhus and Peruvian Cholomec men uses weight to elongate their penises. Men from Dayak tribes in Borneo pierce their glans to enlarge their penis and stimulate their partner. In Topinama of Brazil, men encourage poisonous snakes to bite their penises for 6 months to achieve enlargement.¹ According to Kama Sutra, the symbolic value of penile size as virility, fertility, and strength can trace back to prehistoric Paleolithic period.² Due to the aforementioned cultural believes, modern men often hold the idea regarding their penises as “the bigger the better.” With the enforcement of modern media and entertainment on sexual issues, demands to receive penile augmentation surgery are created. According to consensus, micropenis is the only medical condition which needs surgical correction. In contrast, the majority of patients who request penile augmentation usually have a normal-sized penis.³ The condition of perceiving normal-sized genitals as small is called dysmorphophobia. Therefore, the primary goal of such surgeries is to achieve psychological satisfaction by visual improvements rather than functional improvements. However, the need of surgery is controversial and the long-term surgical outcomes of cosmetic penile augmentation surgery remain uncertain.⁴

In many cultures, the injection of different substance to the genitals is a folk medicine to enlarge the penis. In modern medicine, different augmentation phalloplasty techniques have been reported. As for penile girth enhancement, there has not been any guideline proposed.⁵ The ideal goal for girth enhancement is to create a long-lasting, symmetric increase in girth with minimal incision and limited scaring without compromising erectile function. Many human tissue materials including cartilage, bone, fat, dermis, and dermal fat fascia as well as Vaseline, paraffin, silicon, and hyaluronic acid gel have been used for penile girth augmentation.^6-10 Although injection of artificial material is a simple procedure, long-term complications including implant dislocation and granuloma formation are common.⁷ Penile using human material is more common in recent years and can avoid some of the problems. However, none of the aforementioned techniques has received universal approval. We report our experience using human dermal allograft matrix for penile girth augmentation through a small circumcision incision below the coronary sulcus.

Patients and Methods

From March 2015 to September 2017, a total of 182 patients were prospectively recruited into our cohort after complete physical and psychological evaluation that deemed suitable for penile enhancement. Patients’ age at the time of the surgery was between 20 and 48 years (mean age = 28.7, SD = 2.3). Patients who have received circumcision were also included because our implant is placed between the dartos fascia and the Buck’s fascia deeper than circumcision scar.

In order to select suitable patients for penile augmentation surgery, we followed the screening protocol including:

1. Medical history, physical examination, and hormone profiles.

2. A Chinese translation version of Augmentation Phalloplasty Patient Selection and Satisfaction Inventory Questionnaire (APPSSI)¹¹ was used to identify suitable candidates.

The APPSSI is a validated questionnaire to quantify the severity of the condition, patient’s willingness of surgery, and the post-operative improvement. It can be easily applied to clinical settings. The questionnaire consists of 4 questions, with each having a 5-point scale. A scale of 0 indicates the most severe or worsened condition after surgery and 5 indicates the mildest condition or the most significant improvement. Questions 1 to 3 are preoperative questions and questions 1, 2, and 4 are postoperative. The indication for surgery was a preoperative score of 6 or less. The preoperative scores ranged from 0 (surgery justified) to 12 (surgery not justified), and the postoperative scores ranged from 0 (disappointed) to 12 (excited).

Penis circumference was measured at the mid-length of the penis. Mean was 7.03 cm (6.93 ± 1.00 cm) and 12.1 cm (10.59 ± 1.15 cm) during flaccid and erection, respectively. All patients received human acellular dermal matrix graft under spinal or local anesthesia.

Surgical Technique

All patients received human acellular dermal matrix graft under spinal or local anesthesia. The allograft was preconditioned in normal saline for 20 minutes, and mesh incisions were made to optimize blood flow. The width was equal to the circumference of both corpus cavernosa penis, excluding corpus spongiosum penis. The length of the graft was determined by measuring the length from the tip of the coronary sulcus to the root of penis. Antibiotic prophylaxis was given before anesthesia and continued for 5 days post-operatively. The agent of choice was piperacillin and ciprofloxacin.

Under spinal or local anesthesia, a complete incision below the coronary sulcus to the depth of the Buck’s fascia was made. Then separate the dartos fascia from the Buck’s fascia (Figure 1). The prepared graft was then placed on top of the Buck’s fascia, with the blood-remained side facing Buck’s fascia (Figure 2). The graft was sutured using 4-0 absorbable polyglycolic acid suture to the Buck’s fascia starting proximally (Figure 3). Extra caution needed to be taken when fixing ventrally to avoid injuring the urethra. Once completed, the dartos fascia was restored, the dartos fascia and subcutaneous tissue were sutured with 4-0 absorbable suture, and skin closure is achieved subsequently.

Figure 1.

Separate the dartos fascia from the Buck’s fascia.

Figure 2.

The prepared graft was placed on top of the Buck’s fascia, with the blood-remained side facing Buck’s fascia.

Figure 3.

The graft was sutured to the Buck’s fascia starting proximally.

Before the fixation of the graft distally to the coronary sulcus, maximal traction of the penis is mandatory to ensure adequate length during full erections. After complete repositioning of the shaft, the dartos fascia and subcutaneous tissue were sutured with 4-0 absorbable braided polyglycolic acid–coated suture. The skin was then closed subsequently using 3-0 absorbable polyglycolic suture. No drain was needed. Pre- and post-operative penial circumference were measured (Figure 4A and B). A 10-cm-high elastic bandage dressing is placed around the shaft sparing the glans without compression to ensure adequate blood flow to the graft. The dressing was kept on for 2 weeks at all times and then removed (Figure 5). A Foley catheter was placed before anesthesia and was kept for 1 week to avoid contamination by urine of the dressing or the wound.

Figure 4.

A, Penial circumference pre-operation. B, Penial circumference post-operation.

Figure 5.

Appearance 2 weeks post-operation.

Post-operational education was given to all patients to avoid sexual activity for 8 weeks and minimize the chance of sexual arousal (avoid mature/adult content). Post-operative penile traction was not used based on our previous experience.

Results

All patients tolerated the procedure well. In our series, the mean procedure time was 50 minutes, ranging from 34 to 89 minutes.

The post-operative course was uneventful. No major complications such as severe blood loss requiring transfusion or readmission/return to the operation theatre, infection, injuries to the neurovascular bundle, or post-operational ischemic necrosis were noted. Post-operative pain was managed by using oral non-steroidal anti-inflammatory drugs. Initial seroma and edema subsided within 1 week in all patients. Graft retraction and minor fibrosis were noted in 5 patients (mean retraction: 0.41 cm, range: 0.3-0.6 cm). All these patients had no functional impairment and no evidence of subcutaneous plaque formation. Massive ecchymosis was observed in 5 patients and all resolved by supportive care within 2 weeks.

Post-operative measurements were performed 1 year after the surgery. The mean flaccid girth increased from 6.93 ± 1.00 cm to 8.07 ± 1.06 cm (P < .05), while the mean erect girth increased from 10.59 ± 1.15 cm to 12.79 ± 1.23 cm (P < .05).

Sexual activity was resumed after 8 weeks of surgery. Significant sexual self-esteem and functioning improvement were reported by the majority of patients as shown by marked increase in the mean APPSSI score. The mean preoperative score was 3.08 ± 2.03. The mean post-operative score was 7.66 ± 2.23. The mean difference was 4.58 ± 2.07 (P < .001). In addition, 59 patients previously diagnosed premature ejaculation reported alleviation of their symptoms.

Discussion

The use of allografts has skyrocketed in plastic surgeries recently.¹² Indications for human derma acellular matrix include breast reconstruction, correction of deformities after breast augmentation, repair of abdominal hernias, and repair of oral mucosa. Many studies discussed these applications separately, and each of their complications and technique varies.

Traditionally, penile augmentation is achieved by auto-tissue graft, cell injection, or implantation of natural or artificial materials.¹³ Autologous tissue graft from adjacent tissues of cavernous body is one of the most widely performed surgeries for enhancement of penile girth. It was first reported by Neuber et al in 1893.⁹ The autologous fat graft for penile girth augmentation was first introduced in this report. Another widely used procedure is using oral mucosa for penile girth augmentation or urethra repair.¹⁴ However, the repair of oral mucosa sometimes can be achieved by using allograft. Our opinion is that it is more convenient and less traumatic to use allograft directly. Compared to other soft tissue fillers such as autologous fibroblast, polymethylmethacrylate, and calcium hydroxyapatite, allogenic acellular dermal matrix is relatively lower in cost and is less likely to cause adverse effects.

Compared to penopubic junction incision, our coronary sulcus approach avoids hair bearing and more importantly avascular necrosis of the dorsal penile skin.¹⁴ The arterial blood supply to penile skin and prepuce is provided by the superficial penile arteries branching from the inferior external pudendal arteries.¹⁵ Pubic incisions tend to disrupt the blood supply to the subdermal plexus. In contrast, coronary sulcus incision avoids disruption to the subdermal plexus. Therefore, it is less likely to cause ischemic necrosis. However, this comes at a cost. Because coronary sulcus incision is at higher risk of urine contamination post-operatively, a Foley catheter is mandatory and should be placed for at least 10 days before the wound completely heals.

Surgical treatments to decrease sensation of the glans have demonstrated efficacy for treating PE but are not recommended due to possible sensory loss and rare erectile dysfunction. The major concern of guideline committees is not efficacy but safety. The alleviation of premature ejaculation is thought to be due to decreased stimulation to the dorsal neural complex by additional thickness of subcutaneous tissue. The improvement in sexual self-esteem may also have role as well. This is an interesting finding that requires more study to validate.

In conclusion, compared to autologous dermis-fat graft and xenograft, augmentation phalloplasty using human acellular dermal matrix has several advantages: (1) it avoids harm harvesting site of the autograft; (2) the effects of dermis allograft can last at least 1 year; and (3) acellular dermal matrix is more likely to be accepted by people.