Comparison of Urodynamics Parameters with Intrafascial or Extrafascial Hysterectomy Techniques

Introduction

Urinary incontinence is defined by the International Continence Society as involuntary loss of urine, which is objectively demonstrable and a social or hygienic problem. ¹ Urinary continence is maintained by the work of normal anatomical and neurophysiological bladder, urethra, and pelvic floor functions. ² There are many risk factors that favor urinary incontinence, such as gender, age, race, parity, birth weight, presentation of fetus, obesity, smoking, and menopausal stage.^3,4

Total abdominal hysterectomy is the second most common gynecological operation after cesarean section. ⁵ Although various methods for total abdominal hysterectomy are available, intrafascial and extrafascial methods are the most commonly used. ⁶ Hysterectomy carries the risk of damage to the pelvic splanchnic nerve, which leads to the development of urinary incontinence. The bilateral inferior hypogastric plexa provide sympathetic and parasympathetic innervation to the lower pelvic viscera and are located in proximity to the proximal vagina and distal rectum. During the course of hysterectomy, the pelvic plexus may be at risk of injury in several areas: at the division of the cardinal ligaments, at the blunt dissection of the bladder from the uterus, at the dissection of the paravaginal tissue, and at the removal of the cervix.

The cervix is surrounded by a connective tissue capsule. This connective tissue merges with uterosacral and cardinal ligaments that attach to the pelvic sidewall. This structure was defined by Richardson in 1929 as the pubovesical cervical fascia. ⁷ This fascia includes arterioles and a venous plexus that provides blood to the bladder, cervix, and the upper portion of the vagina. The pubovesical cervical fascia is protected to a greater extent in a total abdominal hysterectomy performed using the intrafascial method compared with the extrafascial method. In the former, the paracervical tissue is clamped and the clamp is placed through this fascial sheet. Thus, the neural network innervating the anterior vaginal wall and bladder neck is protected, in theory.

The intrafascial method is believed to decrease the incidence of injury to the bladder and urethra and is also believed to be a safe technique for removal of the cervix. However, there are insufficient studies comparing the intrafascial and extrafascial methods in terms of the results of bladder functions. Kaya et al. compared the two techniques in terms of urge incontinence and was unable to find a difference between them. ⁸ Gimbel and others compared total abdominal hysterectomy and subtotal hysterectomy in terms of lower urinary system symptoms and found that the syptoms were milder in the subtotal group. ⁹ In a meta-analysis, Robert et al. compared total abdominal hysterectomy and supracercival hysterectomy in terms of urinary incontinence and did not detect a statistically significant difference. ¹⁰

The main objective of this study was to assess the effect of intrafascial and extrafascial methods on bladder functions with a prospective randomized study.

Materials and Methods

The patients who were enrolled in this study were those who presented to the clinics of the department of gynecology and obstetrics at Karadeniz Technical University Medical Faculty Hospital for 2 years who had been given indications of abdominal hysterectomy for benign reasons and/or had bilateral salpingo-oophorectomy performed. Patients were randomly separated into two groups, intrafascial and extrafascial, using a sealed envelope system.

A total of 24 patients were included in the intrafascial group and 27 patients were included in the extrafascial group for planned hysterectomies. Exclusion criteria were as follows: total prolapse, chronic disease that might have led to incontinence (unregulated diabetes mellitus), vertebral pathologies (disk hernia), neurological disorders, and hysterectomy operations performed for malignancies. Our study was approved by the local ethics committee (2010/55) and was supported by Karadeniz Technical University Scientific Research Projects Fund.

The history-taking process included questions about age, height, weight, mode of delivery, previous urogynecological operations, and incontinence. Complete urinalysis, urine culture, postprandial blood sugar, kidney (urea and creatinine), and liver (serum glutamic oxaloacetic transaminase and serum glutamic-pyruvic transaminase) function tests were performed before patient enrollment.

Urodynamics testing was performed according to the results of a control urine culture. Transvaginal sonographic evaluation and pelvic organ prolapse quantification system staging were carried out on all patients. Patients were asked to cough in order for urinary incontinence to be detected (stress test). When the bladder was empty, the anatomy and hypermobility of the bladder neck were examined using a sterile cotton-tipped swab in the dorsolithotomy position with the Q-type test. Neurological examination was performed to assess sacral functions (S2-4).

For all patients, cystometry was performed by a research associate doctor who was responsible for urodynamic testing in our clinic at both the preoperative and sixth month postoperative periods. Evaluation of the cystometric filling phases was carried out. Testing was performed usinga solar multichannel urodynamics system (Medical Measurement Systems) controlled by a Microsoft Windows computer system, both of which were available in our clinic. The results of sensory tests, such as volume at first sensation, volume at normal desire to void, volume at urgency (mL), and for each condition, that is, fullness, intravesical pressure, detrusor pressure, leak points of incontinent patients, were evaluated.

On 51 patients, 10 urodynamics parameters were compared between the pre- and posthysterectomy period. Cases with a measured postvoid residual and emptied bladder were taken in the gynecological lithotomy position. Both single-use double lumen 8F bladder catheters and single lumen 8F rectal catheters were used. NaCl at room temperature was given at an infusion rate of 50 mL/minute.

The volume of bladder filled and first sensation (mL), bladder capacity (mL), and maximum capacity (mL) were noted and are presented in Tables 2 and 3. During bladder filling, detrusor contractions that exceeded 15 cm H₂O and that could not be inhibited were noted. With these findings, the existence of detrusor instability was investigated in several cases. During the same procedure, patients were asked to cough and strain in a progressive manner to investigate leakage of urine through the external meatus. In the case of leakage of urine, the Valsava leak point pressure (VLPP cmH₂0) was noted.

In our study, cases without involuntary detrusor contractions whose VLPP did not exceed 200 cm H₂O were accepted as normal urodynamics results. Abdominal hysterectomy technique was performed extrafascially or intrafascially by two different surgeons at our clinics. ⁶ One surgeon performed the operations using only the intrafascial method, whereas the other surgeon performed surgery using only the extrafascial method.

Extrafascial surgery was performed in accordance with the descriptions of Te Linde. ⁶ As for the intrafascial method, heaney clamps were applied to the uterine artery and then the uterus was held aside by a retractor. Below this level, the cervix was circularly cut through an electrocautery at 40 W cut mode and excised. The pubovesical cervical fascia was preserved in this process. The suture material for the operation was No. 1 Vicryl. For each technique, the duration of operation and the pre- and postoperative hemoglobin values were noted.

The data collected in this study were processed using SPSS (SPSS 21 for Windows) computer software. Data were expressed in the form mean ± standard error. The Wilcoxon signed-rank test was applied to the data that were incompatible with the normal distribution and a paired-samples t-test was applied to suitable data. Any p-value <0.05 was admitted as statistically significant.

Results

A total of 51 patients enrolled in this study. The mean age of these was 48.49 ± 4.87 years. The youngest patient was 38 and the oldest was 62 years. Extrafascial hysterectomy was performed on 27 out of 51 cases and intrafascial hysterectomy was performed on the remaining 24 cases. The mean body mass index (BMI) was 30.316 ± 5.76 kg/m². The mean BMI of the patients in this study was at the lower limit of obesity (>30). Ten patients had a uterus at a gestational size of 12 weeks or older. Eight patients had a unilateral adnexal mass (6 cm or larger) and two patients had bilateral adnexal masses.

Regulated diabetes mellitus was detected in three patients, whereas hypertension was detected in 15 patients. No systemic disease could be detected in 33 of the patients. A total of 36 cases were premenopausal, whereas 15 cases were postmenopausal. None of the patients had received hormone replacement therapy. Two patients smoked for at least 5 years. Nine of the patients had at least five births.

Preoperative hemoglobin values were 12.47 ± 1.28 g/dL and postoperative hemoglobin values were 11.23 ± 1.10 g/dL in the intrafascial group. In comparison, preoperative hemoglobin values were 12.84 ± 1.51 g/dL and postoperative hemoglobin values were 11.79 ± 1.25 g/dL in the extrafascial group. There was no statistically significant difference (p > 0.05) between them. The duration of the operation was 71.04 ± 14.44 minutes for the intrafascial group and 91.85 ± 35.35 minutes for the extrafascial group. There was a statistically significant difference (p < 0.05) between them (Table 1).

Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed on 45 patients. The former surgical procedure alone was performed on six patients. Hysterectomy indications were: abnormal uterine bleeding (n = 14), pelvic mass (n = 8), myoma uteri (n = 13), endometrial polyp (n = 6), endometrial hyperplasia (n = 6), and mixed reasons (abnormal uterine bleeding+myoma uteri+cervical intraepithelial neoplasia 3) (n = 2) (Table 1).

When the urodynamics values of pre- and posthysterectomy periods were compared between the two techniques, no significant change could be found in maximum detrusor pressure, maximum abdominal pressure, vesical compliance, detrusor compliance, maximum vesical pressure, first sensation, normal desire to void, and urge sensation (p > 0.05). In addition, in urodynamic evaluation, the two techniques were compared in terms of urethral closing pressures and no difference was found between the groups. There was no significant difference in both groups in the evaluation of the Q-type test (p > 0.05). With the intrafascial technique, volume and bladder capacity significantly increased after the operation compared with the extrafascial technique (p < 0.05) (Tables 2 and 3).

Urodynamics testing performed before the operations revealed that two patients had stress urinary incontinence and one patient had urge incontinence. No patient developed stress or urge incontinence after the operation. According to the study results, by measuring the weight of urine pad used, no significant relationship was found between the two groups with respect to increase of stress or urge urinary incontinence symptoms and subsequent incontinence after hysterectomy.

Discussion

Hysterectomy may result in pelvic splanchnic nerve injury, and this may lead to the development of incontinence. Numerous studies report that hysterectomy causes urinary symptoms; however, the mechanism of action is not explained. The incidence of urinary symptoms varies between 8% and 80% in different studies. The intrafascial technique is believed to decrease the incidence of ureter injuries. However, there are insufficient studies comparing the effects of intrafascial and extrafascial techniques on bladder functions. The first account in the literature was by Hanley who reported that urinary symptoms increased after total abdominal hysterectomy operations. ¹¹

In a meta-analysis of 45 articles, Brown et al. reported that the rate of urinary incontinence was 40% higher in the posthysterectomy group compared with the nonoperated group. ¹² Lakeman et al. compared abdominal and vaginal hysterectomy in terms of lower urinary system functions and found that symptoms increased in the vaginal hysterectomy group. ¹³

In a study involving 300 patients (intrafascial: 150, extrafascial: 150), Reyna-Hinojosa et al. compared intrafascial and extrafascial hysterectomy in terms of complications and found that the rate of complication was higher in the extrafascial group than in the intrafascial group (38% and 32%, respectively). However, the two techniques were not compared in relation to incontinence. ¹⁴ In our study, no difference was found between the intrafascial and extrafascial hysterectomy techniques in terms of urodynamic parameters and the development of incontinence within 6 months postoperatively.

In a study involving 867 intrafascial hysterectomy operations, Conde-Agudelo investigated postoperative results and complications and revealed that the average duration of operations was 71 minutes and the incidences of surgical site infections and ureter injury were 4% and 0.1%, respectively. ¹⁵ In our study, the mean duration of intrafascial hysterectomy operations was 71 minutes. Surgical site infections or ureter injuries did not occur. The duration of operations was found to be shorter in the intrafascial group and was statistically significant. No difference could be found between the two groups in terms of complications. However, more patients are needed to be able to compare groups in terms of complications and to obtain reliable statistical data.

Demirci et al. evaluated the descent of the urethra using ultrasound at the prehysterectomy period and at the 12-month postoperative period. They found that hysterectomy did not increase the incidence of stress incontinence nor did it distrupt the functions of structures that support the urethra anatomically. ¹⁶

Griffith-Jones et al. detected a minimal increase in stress incontinence after a hysterectomy operation at the 18-month postoperative period. ¹⁷ Similarly, Lalos and Bjerle reported a minimal increase in stress incontinence. ¹⁸ In our study, stress incontinence did not develop in either group at the 6 months postoperative period.

Shiina et al. reported that maximum urethral closure pressure and minimum urethral pressure values decreased after radical hysterectomy and the maximum urethral length became shortened. This was attributed to damage to the hypogastric nerve. ¹⁹

In their study, Long et al. compared abdominal hysterectomy and laparoscopic hysterectomy and found that the maximum urethral closure pressure and the maximum cystometric capacity significantly increased after surgery in both groups. ²⁰

Based on an observation period of 3 years after total abdominal hysterectomy, Gustafsson suggested that hysterectomy did not have any side effects on the urinary system. On the contrary, they reported that symptoms of urge or stress incontinence decreased in the first year and carried on decreasing in this 3-year observation period. ²¹

In the elderly population, frequent urinary incontinence is brought about by decreased estrogen levels and bladder capacity, which are age-related changes. Urinary incontinence affects 17%–45% of adult females, ²² and its frequency is 30%–60% in females >65 years of age. Stress incontinence is more frequent in females <65 years, whereas urge and mixed incontinence are more frequent in females >65 years. ²³

In light of this information it is clear that there is a high risk of pelvic nerve plexus injury during hysterectomy, especially when clamping the lateral sides of the cardinal ligament, when taking the cervix away from the vaginal cuff and when working around paravaginal tissue.

Conclusion

In the intrafascial technique, maximum bladder capacity significantly increased after the operation, compared with the extrafascial technique. Abdominal hysterectomy operations may lead to tissue trauma, injury to the pelvic splanchnic nerve plexus of the bladder and urethra, and changes in urethral function and length, which can be significant after the operation due to inadequate tissue vascularization. This is probably caused by a possible injury that may occur during the cutting procedure of the cardinal ligament, blind dissection to release the bladder from the uterus and sharp dissection to release the uterus from the vaginal cuff. Regarding the development of urinary incontinence, comparison of the two techniques is only possible when performed on homogenous patient groups (as in our study), but also requires an extended number of cases.