A novel biological device to secure and protect neophallus penile prosthesis cylinders and the neourethra for phalloplasty: acellularized while penile Tunica & Glans tissues made from human penis following vaginoplasty

Common risks/challenges related to penile prosthesis placement after phalloplasty in transgender men are: 1. Migration of the penile prosthetic cylinder(s) within the neophallus base and shaft; and 2. Extrusion of a component... [ view full abstract ]

Common risks/challenges related to penile prosthesis placement after phalloplasty in transgender men are: 1. Migration of the penile prosthetic cylinder(s) within the neophallus base and shaft; and 2. Extrusion of a component of the penile prosthetic cylinder(s) through the phallus skin; 3. Infection of anchoring graft material and/or prosthesis, both from the urinary tract, and from bacterial seeding of graft (e.g. Dacron).

To date, no novel device or neourethroplasty technique has been shown to prevent these complications.

1. We propose that human penis specimens (freshly harvested during MtoF GCS vaginoplasty surgery, or cadaveric) can serve as a source from which to harvest intact (i.e. still tubularized) penile Tunica tissue for processing to... [ view full abstract ]

1. We propose that human penis specimens (freshly harvested during MtoF GCS vaginoplasty surgery, or cadaveric) can serve as a source from which to harvest intact (i.e. still tubularized) penile Tunica tissue for processing to render an acellular matrix of the same structure

2. We describe our technique

3. We illustrate how our device could be used at time of phalloplasty using a cadaveric radial artery forearm flap neophallus

We used 5 human penises discarded following MtoF vaginoplasty surgery. While these did not include a portion of the glans, the entire neurovascular bundle, and the proximal urethra, the specimen’s Tunica was completely... [ view full abstract ]

We used 5 human penises discarded following MtoF vaginoplasty surgery. While these did not include a portion of the glans, the entire neurovascular bundle, and the proximal urethra, the specimen’s Tunica was completely preserved and was at least 6 inches in length in all specimens.

We processed the fresh tissues in a chemical bath by a protocol we have developed-- but similar to protocols described in previous studies to create mouse-bladder acellular matrix.

We performed immunohistochemistry (Hemotoxylin, Eosin, Masson’s Trichrome) to assess for residual nuclei, other cellular material, and protein, and to identify collagen.

We placed one of our matrices into a neophallus radial artery forearm flap to illustrate how it could be used.

We inserted inflatable and malleable penile prosthesis cylinders into the acellular matrix and grossly assessed the matrices for strength.

Gross and histologic assessment of human tunica and glans tissues after chemical treatment to render them acellular Use of an inflatable penile prosthesis and a radial artery forearm flap neophallus with neourethra to... [ view full abstract ]

Gross and histologic assessment of human tunica and glans tissues after chemical treatment to render them acellular

Use of an inflatable penile prosthesis and a radial artery forearm flap neophallus with neourethra to demonstrate proposed use

Tunical tissues remained completely intact after chemical processing. Length was preserved. Immunohistochemistry revealed no residual cellular material in 4/5 specimens after chemical processing for 30-days, and questionable... [ view full abstract ]

Tunical tissues remained completely intact after chemical processing. Length was preserved. Immunohistochemistry revealed no residual cellular material in 4/5 specimens after chemical processing for 30-days, and questionable residual protein in 1 focal area of 1 specimen after processing for ~25 days.

Penile prosthetics fit well into the tunica matrices, and the matrices appeared to withstand manual pulling.

There was residual acellular tissue distal to the tunica-end (which could be used to support the glans or a glans-prosthetic).

One detubularized channel of the corpora was fitted around the neourethra, and one intact channel was left in place for future use to accommodate a penile prosthesis cylinder.

Chemical processing for at least 30 days rendered all specimens acellular/devoid of protein. This should render the matrices non-immunogenic. The proposed device (Patents Pending) offers numerous potential safety and... [ view full abstract ]

Chemical processing for at least 30 days rendered all specimens acellular/devoid of protein. This should render the matrices non-immunogenic.

The proposed device (Patents Pending) offers numerous potential safety and durability advantages after FtoM phalloplasty. First, this technique yields two already-intact closed-ended cylinders into which penile prostheses can be inserted; Second, there is sufficient Tunica matrix length to allow the proximal end of the Tunica matrix sheath to be anchored with suture to pubic-area bone; Third: as this is a biological material, the risk of infection is lower than with prosthetic graft material; Fourth: The Tunica serves as a protective barrier to both the prosthesis, and to surrounding neourethra at the time of prosthesis cylinder replacement.
Fifth: This device can be placed at the time of phalloplasty (as we demonstrated). When only one prosthesis cylinder will be used, the extra Tunica-tube can be opened and used to envelope part/all of the neourethra, or, it can be removed.

Furthermore, a small semi-filled (saline) prosthetic could be secured to the Tunica and inserted into residual glans acellular matrix, to better support the neophallus glans.

Further clinical studies, beginning with an animal model of immunogenicity, are warranted.