Abdominal Approaches to Surgery for Female Incontinence

Urinary incontinence in women is common. Its incidence rises after vaginal delivery, apparently as a result of nerve stretch, which can also occur after prolonged straining from constipation. Denervation can lead to incompetence of urethral and anal sphincters and to prolapse of the pelvic floor. Incontinence and prolapse are common and often, but not always, coexist. It is clear that for incontinence to occur, the urethral sphincter must be deficient whether or not a prolapse is present. In some patients with prolapse and bladder base descent, however, rotational compression of the urethra from the prolapse stops any leakage. Following repair of such prolapse, these patients might then begin leaking when the underlying intrinsic sphincter deficiency is unmasked.

The second major cause of urinary incontinence is detrusor instability, a diagnosis based on urodynamic studies and referring to the occurrence of detrusor contractions during the filling phase or provoked by coughing, posture change, etc. It is often associated with symptoms of frequency, nocturia, urgency, and urge incontinence. The presence of detrusor instability preoperatively has been demonstrated by some authors to have a negative prognostic influence on the outcome of surgery. The incidence of detrusor instability detected by continuous ambulatory monitoring is higher than that found on standard cystometry to the extent that some have considered it to be almost normal. In any case, where there are high-pressure overactive bladder contractions, these patients may well require a reduction in their bladder pressures by anticholinergic medication or, in severe cases, by augmentation cystoplasty to ensure adequate bladder capacity, particularly if there is a neurologic cause.

DIAGNOSIS

The diagnosis of urinary incontinence can be made by clinical history and examination of the patient with a full bladder, observing the effects of coughing and straining. The severity of urinary incontinence can be graded.

Urinary leakage can be quantified by standardized pad-weighing tests or by a bladder diary and can be further assessed by the performance of pressure-flow studies, preferably with video screening facilities to demonstrate bladder base and urethral hypermobility or rotational descent during coughing and straining. This will also outline any fistula or urethral diverticulum.

The type of urinary incontinence can be classified on the basis of radiologic findings and the degree of bladder base descent (anatomic incontinence) or whether the urethra appeared wide open as a “stove pipe” (intrinsic sphincter deficiency, ISD) in an attempt to rationalize the type of procedure to be advised.

Measurements of urethral pressures during coughing and straining and measurements of the pressure transmission ratio or assessment of the abdominal leak-point pressure during a Valsalva maneuver have been found useful by some clinicians. Low preoperative maximum urethral closure pressure (MUCP) is more likely to result in a postoperative failure to stop the leakage.1 The abdominal leak-point pressure (ALPP) correlates with the degree of incontinence from the history and from pad-weighing tests; however, the pelvic floor is a complex mechanism, and precisely what happens to it during straining and coughing requires further study.

The presence of detrusor instability is not easy to predict from the history of frequency, nocturia, urgency, and urge incontinence or from examination of the patient, and one must rely on urodynamic studies.

INDICATIONS FOR SURGERY

Essentially, if conservative measures have not succeeded, patients who have genuine stress incontinence and who are bothered by the symptom and who are fit for surgery should be offered it.

The significance of detrusor instability detected preoperatively in predicting the outcome of surgery is controversial. Many have shown that preoperatively detected detrusor instability compromises the results of surgery. Long-term ambulatory monitoring studies show a higher incidence of detrusor instability than conventional cystometry, and the detrusor instability correlated with an increased surgical failure. Many patients with detrusor instability lose their urgency and frequency symptoms postoperatively, though preoperative detrusor instability may persist in 15% to 89% of cases (mean approximately 50%).

Principles of Surgery

Continuous Compression of Urethra

Artificial urethral sphincters and injectable bulking agents produce a continuous compression of the urethra to stop leakage. Submucosal injections of bovine collagen, fat, silicone macroparticles, and other bulking agents have been used to produce coaptation of urethral walls and to increase urethral resistance to leakage; they seem to work best for ISD where there is minimal rotation of the bladder base.

Intermittent Compression

Exactly how other procedures work remains somewhat conjectural but is probably on the same principle of having a backboard behind the urethra that will prevent mobility during coughing and improve the pressure transmission ratio (PTR) of abdominal pressure to the urethra. There is no intrinsic change in the maximum urethral closure pressure postoperatively; hence, nothing is done to improve the efficiency of the intrinsic sphincter mechanism.

These operations produce a suburethral “sling”:

  • Of vaginal wall and periurethral tissues and endopelvic fascia in situ, as in the Stamey, Gittes, Burch, Marshall–Marchetti–Krantz (MMK), and Raz–Peryera operations
  • Of the vaginal wall as a buried strip as in the Raz vaginal sling
  • Using a strip of rectus fascia or fascia lata
  • Of synthetic materials

The principal difference among these procedures is whether the “sling” is sutured to a fixed point, as in the iliopectineal ligament of the Burch procedure and as in the symphysis pubis in the MMK procedure, or to the mobile rectus sheath, as in the pubovaginal sling, Stamey, and Raz operations. The theoretical advantage of being fixed to the mobile rectus sheath is that it will allow for a loose sling at rest that tightens when the abdominal pressure rises and hence resists leakage when it is needed without obstructing voiding.

ALTERNATIVE THERAPY

Conservative therapies including pelvic floor exercises, vaginal cones, and pelvic floor electrical stimulation achieve a success rate that varies between 30% and 70%.3 This improvement may avoid the need for surgery in some patients. It is usually worth trying as a first line of treatment. Success is less likely in the patient who has had previous surgery or radiotherapy and in those with grade 2 or 3 severity of leakage. Hormone replacement therapy may help frequency, urgency, and burning, but its use for incontinence has been disappointing.

SURGICAL TECHNIQUE: RETROPUBIC CYSTOURETHROPEXIES

Burch Colposuspension

Informed consent should follow only after a full explanation of the procedure, length of time of hospitalization and recovery, expected outcomes, and possible complications, as discussed below. Prophylactic antibiotics are administered. My preference is to use a cephalosporin with a spectrum against anaerobic organisms.

The fully anesthetized patient is placed in the modified Lloyd Davies position with hips abducted and minimally flexed. This allows access for preliminary cystoscopy if indicated and for bimanual manipulation intraoperatively. Skin preparation of the abdomen and vagina is performed using Betadine.

A 16-Fr urethral catheter with 7 ml instilled into the balloon is placed on free drainage. Through a Pfannensteil incision 1 cm above the symphysis pubis, the rectus fascia is incised transversely, and the recti are separated. The bladder is swept off the back of the symphysis pubis and the iliopectineal ligament, exposing it and the obturator internus and levator ani muscles. Care is required to avoid damage to the abnormal obturator veins, if present. This dissection is easy in a first approach but can be difficult if adhesions are present following previous surgery. Care is required to avoid perforating a thin-walled bladder adherent to the bones. Keeping close to the bone helps to avoid this. Some surgeons advocate intravesical installation of methylene blue to detect any transgression into the lumen.

With the two fingers of the operator’s left hand in the vagina, the lateral fornix is tented up, and the endopelvic fascia overlying the vaginal fornix, well lateral to the bladder, is buttonholed; this allows the vagina and its plexus of veins to be mobilized medially. The dissection should start well laterally to avoid the ureter and the bladder. Blunt dissection with the Riches diathermy forceps develops the appropriate plane lateral to the bladder neck as defined by palpation of the Foley catheter balloon, and this exposes the pale white tissue of the vagina and allows any venous bleeding to be cauterized without changing instruments. Mobilization is done on both sides. A row of usually three nonabsorbable sutures (size 1 nylon) are placed full thickness of vagina up through the iliopectineal ligament. These are then tied before sutures are placed on the opposite side to enable correct positioning.

It is important not to make the suspension too tight, and it is not necessary to approximate the vagina to the iliopectineal ligament. Often the sutures “bow-string,” particularly after previous vaginal repair or vaginal hysterectomy, as of course they always do in any of the needle suspension procedures.

Where an enterocele is present, this can be surgically managed with a Muskowitz procedure in which the pouch of Douglas is obliterated intraperitoneally by encircling sutures at serial levels. In the prevention of this complication of the Burch procedure, some have advised plication of the round ligament or, if a hysterectomy has been previously undertaken, of tightening the uterosacral ligaments.

A suction drain is left in the retropubic space, and a suprapubic catheter is inserted to enable measurements of postvoid residuals postoperatively. After balloon inflation, the catheter should be withdrawn against the vault of the bladder to avoid its tip irritating the trigone and causing postoperative urgency. The rectus muscles are approximated with interrupted 2-0 synthetic absorbable sutures without tension, and the rectus fascia is closed transversely with continuous 0 suture.

Postoperatively the suction drain is removed, usually by day 2; the suprapubic catheter is clamped, and a trial of voiding is commenced. It is removed when the residuals are less than 100 ml or less than one-third of the bladder capacity. Patients are discharged by day 5, and by then most are voiding satisfactorily; if there is any doubt, the patient is taught intermittent self-catheterization until voiding efficiency is restored.

Marshall-Marchetti-Krantz Procedure

This procedure, described in 1949, involves retropubic dissection through a Pfannensteil incision as for the Burch procedure, and the edges of the urethra are sutured to the fibrocartilage of the symphysis pubis. Serially, the row of sutures is continued onto the anterior surface of the bladder in the perception that this would alleviate prolapse and descent of the bladder base. There is some risk of damage to the urethra as the sutures pass through its lateral wall, and most surgeons have modified the original procedure to take in the periurethral tissue rather than the edges of the urethra. There are also technical difficulties in some patients because of the very thin periosteum through which to place the sutures.

Suburethral Slings

Patients with rotational descent and adequate vaginal capacity are suitable for either a Burch colposuspension or a pubovaginal sling, but if the vaginal capacity is reduced, a pubovaginal sling may be more appropriate. These retropubic procedures use a fascial strip from the rectus fascia as a suburethral sling with each end sutured to the rectus sheath. This technique has been largely superseded by a vaginal approach to avoid the retropubic . In the abdominal approach for this procedure, a strip of rectus fascia 1.5 cm wide is taken from the upper margin of the Pfannensteil incision. The bladder is mobilized, and a tunnel is developed between the vagina and bladder neck and upper urethra, using the balloon of the catheter as a guide. The sling is passed through this tunnel, each end of the strip is sutured with 1 nylon, and the sutures at each end are brought out and tied anterior to the rectus, 1 to 2 cm lateral to the midline, and low down, 1 cm above the symphysis. The length of the strip is probably not critical to the procedure, but it would seem reasonable to use a strip approximately 5 to 10 cm in length. The nylon sutures can be passed up to the appropriate site using the Stamey needle. It is important to ensure that the sling is not too tight, to avoid urethral compression.

Laparoscopic Burch Colposuspension

The patient is admitted in the morning of surgery, having had nothing by mouth from midnight of the night before. Below-knee compression stockings are fitted, and a shave is performed to just below the upper border of the pubic symphysis (midpubic shave). No bowel preparation is necessary for this procedure. A suitable premedication is given, and prophylactic antibiotics are given with the induction of anesthesia as a single dose.

A general anesthetic is preferred for complete relaxation. Pneumatic calf stimulators are placed once the patient is asleep. The low lithotomy position is employed with slight hip flexion and abduction. The lower abdomen and vagina are scrubbed and prepared in the usual manner, and a Foley catheter is placed on free drainage. Surgical drapes are placed to leave the abdomen below the umbilicus and perineum exposed. The surgeon stands on the patient’s left, and the assistant and a scrub nurse on the patient’s right. A Mayo table is placed between the patient’s legs, and this contains the trocars and instruments necessary during the procedure. Two video monitors are generally employed, one each for the surgeon and assistant, at the foot of the bed.

The procedure commences with a 12-mm incision, which is placed midway between the umbilicus and the pubic symphysis. It is extended down to the fascia, which is cleared away by finger dissection. The fascia is penetrated with a fine arterial forceps, and the surgeon’s index finger is used to clear the extraperitoneal space so that the pubic symphysis can be clearly felt. It is important to be careful not to puncture the peritoneum during this maneuver. Two stay-sutures are placed to the fascial opening; then the retroperitoneal dilating balloon on a catheter introducer is passed into the space created, and 600 ml of saline is placed in the balloon. This remains inflated for several minutes while the remainder of the laparoscopic instrumentation is set up, including the video camera. The balloon is then deflated, and the Hasson cannula placed and secured with stay-sutures. The space is then inspected with the laparoscope. The room is then darkened, and the light source turned up to the maximum. The remaining two trocars are placed in the left lower quadrant. It is important to avoid the vessels that are transilluminated during this maneuver. The 5-mm trocar is placed 2 cm above the symphysis at the lateral border of the left rectus abdominis muscle. The 10-mm trocar is placed between the two previous trocars avoiding obvious blood vessels.

With the assistant’s finger in the vagina elevating the tissue adjacent to the bladder neck, which can easily be identified using the balloon of the Foley catheter as a guide, the endopelvic fascia is cleared of its fatty tissue. The grasping forceps are in the surgeon’s left hand, and the endosurgical scissors in his or her right. Once this is completed, the needle holder is used to introduce the long length of 2-0 Ticron suture down the 10-mm port. The needle is grasped at an appropriate angle, and a large bite of this tissue adjacent to the bladder neck is obtained. The suture needle is then cut off. The percutaneous suture passer is then passed under direct vision into the extraperitoneal space just above Cooper’s ligament. It is then placed through the ligament. The end of the suture is passed through the eye of this needle and drawn up through the ligament. Then, the suture material is freed from the suture passer, and this is withdrawn. The free end of the suture, which now passes through both the vaginal tissue and Cooper’s ligament, is then grasped with the needle holder and drawn out through the 10-mm port. An extraperitoneal knot is then tied, and this is passed down to be placed snugly on Cooper’s ligament. The suture material is then cut, and two further intracorporeal knots are tied to secure this extracorporeal knot. The assistant’s finger elevates the tissues throughout this maneuver. Further fixation can be obtained with a 15-cm length of 2-0 Ticron suture on a needle that is passed through both Cooper’s ligament and the vaginal tissues with the knots being tied intracorporeally. The procedure is then repeated on the patient’s left side in an identical manner.

An alternative to this technique involves a 15-cm length of suture, which is prepared by tying a small loop at the free end. The suture is then passed through the 10-mm port with a needle holder and then through the tissue at the level of the bladder neck. The needle is then passed through this loop at the end of the suture, and it is snugged down onto the tissues. A further bite of paravaginal tissue can then be taken to form a helical suture, and the needle is then passed through Cooper’s ligament. A Lapra-Ty clip can then be placed onto the suture just as it exits the ligament. A second pass through Cooper’s ligament and a second Lapra-Ty clip can also be placed for extra security.

The patient is able to eat and drink once she recovers from the effects of the anesthetic. Analgesic and antiemetics are given as required, though opiates are usually unnecessary. The Foley catheter remains in the bladder on free drainage until 6 o’clock the next morning, at which time it is removed, and if the patient is able to void comfortably on several occasions following this, she is discharged from the hospital. Rarely, intermittent self-catheterization will be required for the first few days if voiding is not satisfactory. Residual urine volumes are not routinely measured. No further antibiotic prophylaxis is employed.

OUTCOMES

Complications

Urethral obstruction after successful surgery occurs in about 10% of cases. To prevent it, care should be taken to avoid elevating the bladder neck too high or tying sutures with undue tension. Intermittent self-catheterization is best used in these cases, and generally, with time, voiding dysfunction usually resolves within about a week. It may persist longer. If dysfunction persists for more than 3 to 6 months, the sutures can be taken down, and, following cystolysis, a vagino-obturator shelf can be considered.

Postoperative voiding difficulties may be predicted by preoperative voiding problems. However, some acontractile bladders at preoperative study can be shown to contract postoperatively. Those with low preoperative voiding pressures (less than 15 cm of water) were more likely to have problems.7 Measurement of isometric pressure at the clinical stop test was not found to be helpful in predicting postoperative voiding dysfunction.

De novo appearance of detrusor instability postoperatively has been observed in 10% to 20% of cases. Why this should occur is unclear, but ambulatory continuous monitoring studies show a higher preoperative incidence of detrusor instability, and perhaps the surgery unmasks this by changing afferent inputs from the pelvic floor. In the patient with urgency and urge incontinence postoperatively, one should exclude infection and obstruction. Urodynamic studies should be performed to determine the presence of instability. Cystoscopy should be undertaken where the problem persists, as occasionally a stitch will erode into the bladder. In management, if instability is the only problem, then anticholinergics are often helpful. In the rare cases where this does not suffice and instability remains a problem, then a clam cystoplasty can be considered.

Dyspareunia following pelvic floor surgery is not uncommon and is either downplayed or not included in the subjective symptomtology in most series. Where the vagina was narrow or shortened before the incontinence surgery, dyspareunia may occur as a result of the posterior ridge that mirrors the anterior suspension of the anterior vaginal wall. Usually this will settle in time.

The question of whether vaginal delivery should be allowed after a successful incontinence surgery is often stated, but the evidence is lacking. This has led to most patients who have had a successful outcome from surgery being advised by their obstetrician to consider a cesarean section rather than risk breaking it down. The magnitude of this risk has never been properly substantiated.

After the Burch procedure and needle suspension operations, pain occurs in around 10% and is usually caused by the tension of the sutures. Mostly it decreases with time, but occasionally it persists, and the sutures have to be removed. Another rarer cause of pain is osteitis pubis.

Results

There is a discrepancy between the results as told us by the patients and those obtained from objective tests of clinical examination, pad-weighing tests, or video pressure-flow studies postoperatively. Often it is not clear in the literature how the results are in fact assessed. In a collected series only 4,815 of 20,481 (23.5%) had had their results of surgery objectively assessed.

Results are probably best assessed by a health professional independent of the surgeon, as patients often unwittingly confound the results as stated. They often want to please the surgeon, the one whom they chose and whose advice they accepted. They might feel guilty about hurting the surgeon’s feelings or fearful that if they complain of continuing problems, the surgeon might want to do all that again, or even something worse. Patients often enhance the results, and although they may indeed be dry, that might be at the expense of stopping jogging, aerobics, or golf, etc. These factors make comparison of outcomes from different procedures quite difficult.

There is not a perfect operation for female urinary incontinence, but the results in achieving continence are quite good at 5 years. The results tend to diminish in time, although the Burch operation and pubovaginal slings tend to hold up as well as most others.

Patients with persistent or recurrent urinary incontinence should be thoroughly reassessed. This includes history, examination, bladder diary, pad-weighing tests, and urodynamic studies to detect any instability, fistula, etc. If genuine stress incontinence is the reason for failure, then the operation can be repeated. Or, if the urethra is “stove-pipe” and fixed, then there are the options of injecting a suburethral bulking agent such as collagen or of repeating the colposuspension or vaginal sling. In gross cases, some have advocated a reduction vesicourethroplasty. In some cases the artificial urethral sphincter can be considered.

Causes of failure include incorrect placement of sutures too high or too low in relation to the bladder neck, sutures cutting out, atrophy of the periurethral and vaginal tissues contributing to the sling, or sphincter damage as might occur in the Marshall–Marchetti–Krantz procedure, where the sutures might have been placed in the wall of the urethra. The urethra may be held open by scar tissue following the first procedure, and a full urethrolysis needs to be considered at the second procedure to avoid this.

A history of previous hysterectomy; obesity, but excluding morbid obesity; parity; or age had no apparent influence on the outcome, but results were slightly better in those who had no past history of prior incontinence surgery.

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