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Mirastschijski et al. Plast Aesthet Res 2020;7:45 I http://dx.doi.org/10.20517/2347-9264.2020.44 Page 11 of 13

artery, however, they did not discern that these arteries were running in parallel in two separate septa. A
[24]
study by Angspatt et al. showed that the anterior scrotal artery supplies 62.5%-100% (mean 75.9%) of the
scrotal skin in the anteroposterior dimension and 66%-100% (mean 88%) in the superoinferior dimension.
The main blood supply runs through the branches of the external pudendal artery. The remaining tissue
was supplied by the posterior scrotal artery. Seemingly, the dominant vascular system perfusing the scrotal
tissue derives from the external pudendal artery with the anterior and lateral scrotal branches. The internal
pudendal artery provides branches to the dorsal part of the scrotum and the septum.

During embryonal development, the external genitalia in both sexes originate from the genital tubercles
and swellings. Under the influence of male or female hormones, genital swellings differentiate into the
[25]
scrotum (dihydrotestosterone) or labia majora (estrogen) . In females, the process continues with
separation of the genital swellings that surround the vaginal vestibulum; in the male embryo, both genital
[25]
swellings fuse in the midline to become the scrotal sac . The scrotal septum depicts the fusion line of both
genital swellings, and it is not surprising that it consists of two thin membranes with identical anatomical
structure. Genital development is indeed common knowledge, however, the existence of two scrotal septa
including a mirroring vasculature has not been described so far.

An island flap with dual arterial blood supply implies a safe surgical technique for penile shaft coverage. Both
occlusion or disruption of the blood supply via one vessel will not jeopardize flap survival due to redundant
blood supply by the twin artery. Our assumption is based on angiosome studies by Angspatt et al.
[24]
[26]
and previous reports on the anatomy of the posterior scrotal artery . The septal scrotal artery is a branch
of the posterior scrotal artery deriving from the perineal artery [Figure 2E]. In our anatomical studies, we
could not clearly detect such angiosomes. Because the posterior scrotal artery anastomoses with branches
of the lateral scrotal artery, it is conceivable that the angiosome may include the skin area around the raphe
scroti along the septum scroti.

Interestingly, there are two further reports on scrotal island flaps with pedicles different from ours.
[27]
Karim et al. used a dorsal scrotal island flap supplied by the dorsal scrotal vessels for perianal defect
[28]
coverage. Fakin et al. reconstructed patients with penile granuloma with a ventral scrotal flap pedicled on
the deep external pudendal artery. Abundant bilateral cutaneous perfusion from different vascular sources
with highly elastic and excessive tissue renders the scrotum an ideal donor area for reconstructive surgery.
To avoid testicular torsion or ascension due to diminished volume of the scrotal sac after skin and septal
resection, bilateral orchidopexy is recommended and should be routinely performed.

Nerves concomitant to the septal arteries provide cutaneous sensation over the ventral aspect of the
scrotum in proximity to the midline where the flap is harvested. This unexpected finding was reported by
our patients who were puzzled to locate the sensation of the neo-penile skin to the scrotal sac [Table 2].
In fact, the brain’s plasticity enables even elderly patients to learn the new location of the skin within a
[29]
few weeks, a well-known feature from reconstructive hand surgery . In larger patient cohorts, objective
measurement tools such as the Semmes Weinstein test for sensitivity analysis are recommended to evaluate
clinical findings in a standardized way.

A general drawback of island flaps is the cessation of lymphatic drainage due to complete cutaneous
excision with loss of lymphatic continuity [Table 2]. Consequently, a prolonged lymphedema is noticed
until new lymphatic vessels have developed. To minimize swelling and the risk of wound dehiscence,
a protective and stabilizing dressing is positioned circumferentially around the penis with fixation
to the perineum and glans. After removal, manual lymphatic drainage and compression therapy are
recommended. The highly elastic scrotal skin provides sufficient tissue to cover the entire penile shaft and
can form a neo-prepuce as well. In case of patients with Lichen sclerosus et atrophicus (balanitis xerotica