Disorders of the Ureters
Abnormalities in structure of the ureter include subdivision at the renal pelvis and constricted or abnormally narrow
parts, called strictures. Abnormal pressure from tumors or other outside masses may cause ureteral narrowing. Obstruction also may be caused by stones from the kidneys, or kinking of the tube because of a dropping of the kidney, a condition known as renal ptosis. In cases of ureterocele, the end of the ureter bulges into the bladder (Fig. 18-12). The result is urinary obstruction that leads to distention of the ureter (hydroureter) and renal pelvis (hydronephrosis). The usual cause of ureterocele is a congenital (present at birth) narrowing of the ureteral opening.
Ureteral Stones The passage of a small stone along the ureter causes excruciating pain, called renal colic. Relief of this pain usually requires morphine or an equally powerful drug. The first “barber surgeons,” operating without benefit of anesthesia, were permitted by their patients to cut through the skin and the muscles of the back to remove stones from the ureters. “Cutting for stone” in this way was relatively successful, despite the lack of sterile technique, because the approach through the back avoided the peritoneal cavity and the serious risk of peritonitis.
Figure 18-12 Ureterocele. The ureter bulges into the bladder. The resulting obstruction causes urine to back up into the ureter and renal pelvis.
Disorders Of the Bladder
A full (distended) bladder lies in an unprotected position in the lower abdomen, and a blow may rupture it, necessitating immediate surgical repair. Blood in the urine is a rather common symptom of infection or tumors, which may involve the bladder.
Cystitis Inflammation of the bladder, called cystitis, is 10 times as common in women as in men. This may be due, at least in part, to the very short urethra of the female compared with that of the male. The usual path of infection is that bacteria ascend from the outside through the urethra into the bladder. The common contaminants are colon bacteria, such as E. coli, carried to the urethra from the anus. Urinary stasis and catheterization to remove urine from the bladder are other possible sources of infection.
Pain, urgency to urinate, and urinary frequency are common symptoms of cystitis. Another type of cystitis, called interstitial cystitis, may cause pelvic pain with discomfort before and after urination. The tissues below the mucosa are involved. The disease can be diagnosed only with the use of a cystoscope, a type of endoscope used to examine the bladder (Fig. 18-13). Because no bacteria are involved, antibiotics are not effective treatment and may even be harmful. Obstruction by an enlarged prostate gland in a male or from pregnancy may lead to urinary stasis and cystitis. Reduction of a person’s general resistance to infection, as in diabetes, may also lead to cystitis. The danger of cystitis is that the infection may ascend to other parts of the urinary tract.
Figure 18-13 Cystoscopy. A lighted cystoscope is introduced through the urethra into the bladder of a male subject. Sterile fluid is used to inflate the bladder. The cystoscope is used to examine the bladder, remove specimens for biopsy, and remove tumors.
Tumors: Tumors of the bladder, which are most prevalent in men older than 50 years of age, include benign papillomas and various kinds of cancer. About 90% of bladder tumors arise from the epithelial lining. Possible causes include toxins (particularly certain aniline dyes), chronic infestations (schistosomiasis), heavy cigarette smoking, and the presence of urinary stones, which may develop and increase in size within the bladder. Blood in the urine (hematuria) and frequent urination, in the absence of pain or fever, are early signs of a bladder tumor. A cystoscopic examination (see Fig. 18-13) and biopsy should be performed as soon as these signs are detected. Treatment includes removal of the tumor, which may be done cystoscopically, and localized chemotherapy. More serious cases may require irradiation. Removal before the tumor invades the muscle wall gives the best prognosis. If it is necessary to remove the bladder in a cystectomy, the ureters must be vented elsewhere. They may be diverted to the body surface through a segment of the ileum, a procedure known as an ileal conduit (Fig. 18-14), or diverted to some other portion of the intestine. Alternatively, surgeons may create a bladder out of a section of the colon.
Figure 18-14 Ileal conduit. The ureters are vented through a segment of the ileum to open at the body surface through an ileostomy.
Urinary Incontinence: Urinary incontinence refers to an involuntary loss of urine. The condition may originate with a neurologic disorder, trauma to the spinal cord, weakness of the pelvic muscles, impaired bladder function or medications. Different forms of urinary incontinence have specific names:
* Stress incontinence is due to urethral incompetence that allows small amounts of urine to be released when an activity increases pressure in the abdomen. These activities include coughing, sneezing, laughing, lifting or exercising.
* Urge incontinence, also called overactive bladder, results from an inability to control bladder contractions once the sensation of bladder fullness is perceived.
* Overflow incontinence is due to neurologic damage or urinary obstruction that causes the bladder to overfill. Excess pressure in the bladder results in involuntary loss of urine.
* Enuresis is involuntary urination, usually during the night (bed-wetting).
Some treatment approaches to incontinence include muscle exercises, dietary changes, biofeedback, medication, surgery or, in serious cases, selfcatheterization.