- greater difficulty identifying the ureter
- a steeper learning curve
- more frequent use of energy to hemostatically divide pedicles, with the potential for thermal injury
- less traction–countertraction, resulting in dissection closer to the ureter
- management of complex pathology.
Although the overall incidence of ureteral injury during adnexectomy is low, it is probably much higher in women undergoing this procedure after a previous hysterectomy or in the presence of complex adnexal pathology.
When injury is likely
Compromised exposure, distorted anatomy, and certain procedures can heighten the risk of ureteral injury. Large tumors may limit the ability of the surgeon to visualize or palpate the ureter (FIGURE 1). Extensive adhesions may cause similar difficulties, and a small incision or obesity may hinder identification of pelvic sidewall structures.
A number of pathologic conditions can distort the anatomy of the ureter, especially as it relates to the female genital tract:
- Malignancies such as ovarian cancer often encroach on and occasionally encase the ureter
- Pelvic inflammatory disease, endometriosis, and a history of surgery or pelvic radiotherapy can retract and encase the ureter toward the gynecologic tract
- Some masses expand against the lower ureter, such as cervical or broad-ligament leiomyomata or placenta previa with accreta
- During vaginal hysterectomy for complete uterine prolapse, the ureters frequently extend beyond the introitus well within the operative field
- Congenital anomalies of the ureter or hydroureter can also cause distortion.
Even in the presence of relatively normal anatomy, certain procedures predispose the ureter to injury. For example, radical hysterectomy involves the almost complete separation of the pelvic ureter from the gynecologic tract and its surrounding soft tissue. When pelvic pathology is significant, the plane of dissection will always be near the ureter.
FIGURE 1 Access to the ureter is obstructed, putting it in jeopardy
Large tumors may limit the ability of the surgeon to visualize or palpate the ureter.
Prevention is the best strategy
At least 50% of ureteral injuries reported during gynecologic surgery have occurred in the absence of a recognizable risk factor.2,7 Nevertheless, knowledge of anatomy and the ability to recognize situations in which there is an elevated risk for ureteral injury will best enable the surgeon to prevent such injury.
When a high-risk situation is encountered, critical preventive steps include:
- adequate exposure
- competent assistance
- exposure of the path of the ureter through the planned course of dissection. Dissecting the ureter beyond this area is usually unnecessary and may itself cause injury.
Skip preoperative IVP in most cases
The vast majority of women who undergo gynecologic surgery do not benefit from preoperative intravenous pyelography (IVP). This measure does not appear to reduce the likelihood of ureteral injury, even in the face of obvious gynecologic disease. However, preoperative identification of obvious ureteral involvement by the disease process is useful. In such cases, the plane of dissection will probably lie closer to the ureter. One of the goals of surgery will then be to clear the urinary tract from the affected area.
When there is a high index of suspicion of an abnormality such as obstruction, intrinsic ureteral endometriosis, or congenital anomaly, preoperative IVP is indicated.
A stent may be helpful in some cases
Ureteral stents are sometimes placed in order to aid in identification and dissection of the ureters during surgery. Some authors of reports on this topic, including Hoffman, believe that stents are useful in certain situations, such as excision of an ovarian remnant, radical vaginal hysterectomy, and when pelvic organs are encased by malignant ovarian tumors. However, stents do not clearly reduce the risk of injury and, in some cases, may increase the risk by providing a false sense of security and predisposing the ureter to adventitial injury during difficult dissection.
Anticipate the effects of disease
The surgeon must have a thorough knowledge of the gynecologic disease process as it relates to surgery involving the urinary tract. For example, an ovarian remnant will almost always be somewhat densely adherent to the pelvic ureter. When severe endometriosis involves the posterior leaf of the broad ligament, the ureter will often be fibrotically retracted toward the operative field.
Certain procedures have special challenges. During resection of adnexa, for example, it is important that the ureter be identified in the retroperitoneum before the ovarian vessels are ligated. During hysterectomy, soft tissues that contain the bladder and ureters should be mobilized caudally and laterally, respectively, creating a U-shaped region (“U” for urinary tract, FIGURE 2) to which the surgeon must limit dissection.
FIGURE 2 During hysterectomy, mobilize the bladder and ureter
Mobilize the soft tissues that contain the bladder and ureters caudally and laterally, respectively, creating a U-shaped region. During division of the paracervical tissues, the surgeon must remain within this region.