Surgical Anatomy of the Bladder and Ureter
The bladder is a hollow, muscular organ, its main function being that of a reservoir. Secondary to the distensibility of its muscular wall, it has the inherent ability to maintain a low pressure even when fully distended so as to maximum capacity. When empty, the adult bladder lies behind the pelvic symphysis and is a pelvic organ. When full, the bladder rises well above the symphysis and can readily be palpated and percussed. The empty bladder is described as having an apex, a superior surface, two anterior lateral surfaces, a base or posterior surface, and a neck (Figs. 86–1 and 86–2). The apex reaches a short distance above the pelvic bone and ends with a fibrous cord derivative of the urachus, which originally connects the bladder to the allantois. This fibrous cord extends from the apex of the bladder to the umbilicus between the peritoneum and the transversalis fascia. It raises a ridge of peritoneum called the median umbilical ligament. The superior surface is the only surface of the bladder covered by peritoneum. The superior surface of the bladder is in relation to the uterus and the ileum. The base of the bladder faces posteriorly and is separated from the rectum by the uterus and vagina. The anterior lateral surfaces on each side of the bladder are in relation to the obturator internus, levator ani muscles, and pelvic bone (Figs. 86–3 and 86–4). However, the bladder is actually separated from the pelvic bone by the retropubic space (see Chapter 31). The interior of the bladder is completely covered by several layers of transitional epithelium (see Fig. 86–1). A loose underlying connective tissue permits considerable stretching of the mucosa; for that reason, the mucosal lining is wrinkled when the bladder is empty but quite smooth and flat when the bladder is distended. This arrangement exists throughout except over the trigone area, where the mucous membrane is fairly adherent to the underlying musculature of the superficial trigone. This is why the trigone is always smooth whether the bladder is full or empty (see Fig. 86–4).
The ureter is about 28 to 32 cm long in the adult and runs half its course in the abdomen and half in the pelvis after it crosses the iliac vessels (Fig. 86–5). During abdominal or vaginal surgery, the ureter may be inadvertently bruised, lacerated, ligated, partially or completely transected, or mishandled in such a way that the blood supply is disturbed and necrosis develops at a later time. The anatomy of the entire ureter has been reviewed in and Chapter 36 and Chapter 37.
