Fig. 24.1
Evaluation of the new female anatomy in a 25-year-old male to female (MtoF) transsexual investigated 8 days after sex reassignment surgery (SRS). The neovagina and the rectum are distended with gel. Imaging has been performed with the vaginal tutor (T) inserted. (a) Midsagittal T2-weighted magnetic resonance (MR) image shows the new female normal anatomy of the patient. The neovagina has an adequate length of 11 cm and inclination from front to rear. Note the prostate (curved arrow), rectovaginal septum (arrowhead), anal canal (C), bladder (B), urethral remnant (arrows), neoclitoris (asterisk), and bulbocavernous muscle (open arrow). (b, c) Appearance of the same anatomical features on axial T2-weighted MR images
A minor but relatively common complication of MtoF SRS is neovaginal prolapse (Fig. 24.2). Diagnosis is clinical, but MR imaging is indicated when associated inflammatory ischaemic changes are suspected. Abscesses are frequently localised in the labia (Fig. 24.3) [4], but can also involve the dissected rectoprostatic fascia and the tissues around the urethral stump. They are usually treated conservatively with incision and drainage and with cephalosporin-based antibiotics until complete remission. In a minority of cases wound exploration is required.
Fig. 24.2
Prolapse of the neovagina in a 35-year-old MtoF transsexual investigated 5 days after SRS. The patient was investigated because ischaemia of the neovaginal wall was clinically suspected. Midsagittal fat-suppressed T1-weighted MR image obtained after the administration of a gadolinium-based contrast agent shows a partially prolapsed, non-ischaemic neovagina (V) in the lower portion of the space created between the prostate and the rectum (arrowheads). Fluid (curved arrows) is also shown anterior to the urethral remnant (arrows)
Fig. 24.3
Abscess formation in the labia of a 22-year-old MtoF transsexual investigated 9 days after SRS. Axial T2-weighted (a) and fat-suppressed T1-weighted MR image (b) obtained after the administration of a gadolinium-based contrast agent show fluid collections within the labia (arrowheads) with an air bubble (curved arrow) and a peripheral rim of enhancement consistent with abscesses. The patient was treated with systemic antibiotics and subsequently underwent successful percutaneous drainage
24.2.2 Thickness of the Rectovaginal Septum
During MtoF SRS the neovagina is obtained by dissecting the space between the rectum posteriorly and the prostate anteriorly. This is the most dangerous phase of the operation because accidental rectal injuries are possible with fistula formation. The bulbocavernous muscle may be used to reinforce the distal portion of the septum and reduce the risk of fistulisation.
24.2.3 Evaluation of the Neoclitoris
Magnetic resonance imaging allows excellent evaluation of the neoclitoris early after SRS and later during the follow-up (Fig. 24.4). Variations in the surgical technique can be identified, such as preservation of the dorsal aspect of the tunica albuginea, isolated or with a small amount of cavernosus tissue (Fig. 24.5). Bleeding of the tissues used to manufacture the neoclitoris is common in the early postoperative period (Fig. 24.6). It is usually self-limiting, but may occasionally require medical treatment, interventional procedures or surgical revision. Fat-saturated T1-weighted images obtained after gadolinium contrast medium administration are the most informative when evaluating the urethral stump, glans remnant, neurovascular bundle, blood extravasation, and ischaemic changes.
Fig. 24.4
Evaluation of the neoclitoris in a 41-year-old MtoF transsexual investigated 8 days after SRS. (a) Midsagittal T1-weighted MR image obtained after the administration of a gadolinium-based contrast agent shows the urethral remnant (arrows), the dorsal neurovascular bundle of the penis (curved arrow) folded up under the pubic subcutaneous fat to form the mons veneris, and the neoclitoris (asterisk), which is in the natural anatomical position of the female clitoris. (b, c) Axial gadolinium-enhanced T1-weighted images at the level of the neoclitoris (a) and of the mons veneris (b) show: (b) the urethral remnant (arrows) opened, incised distally in a Y shape, and sutured around the neoclitoris (asterisk), and (c) the neurovascular bundle of the penis within the pubic subcutaneous fat. P prostate
Fig. 24.5
Variation of the surgical technique for creating the neoclitoris in a 22-year-old MtoF transsexual. Midsagittal fat-suppressed T1-weighted MR image obtained after the administration of a gadolinium-based contrast agent shows the urethral remnant (arrows), the dorsal neurovascular bundle of the penis (curved arrow) and the neoclitoris (asterisk). A strip of the dorsal portion of the tunica albuginea has been preserved, which is visible as a hypointense line (arrowheads) stuck on the neurovascular bundle. P prostate
Fig. 24.6
Male to female SRS complicated by bleeding of the wedge of the glans when the neoclitoris was manufactured. MR imaging was performed 2 days after the operation. Axial T1-weighted image shows a small extravasation of blood (curved arrow) surrounding the neoclitoris (arrowhead). The haematoma was reabsorbed spontaneously within 1 week
24.2.4 Evaluation of Cavernosal and Spongiosal Remnants
In early surgical variations for MtoF SRS a neoclitoris was not created. The crura of the corpora cavernosa and the bulbus of the corpus spongiosum were preserved as they were thought to increase sensitivity and enhance sexual satisfaction. Long-term experience has demonstrated, on the contrary, that engorgement of the residual erectile tissue during sexual arousal and foreplay causes the patient discomfort and dyspareunia during penetration. MR imaging allows an excellent depiction of the remnants and of their relationship with the surrounding structures [1, 2]. T2-weighted images obtained after ultrasound-guided PGE1 injection are the most informative (Fig. 24.7).
