Urethral pressure reflectometry and pressure profilometry in healthy volunteers and stress urinary incontinent women

Measurement of Urethral Closure Function in Women With Stress Urinary Incontinence

Rationale:Stress urinary incontinence (SUI) refers to the involuntary leakage of urine when abdominal pressure increases. Midurethral slings (MUS) have become the main surgical method for treating SUI, but no quantitative standard for the degree of sling tightness during operation exists. We achieved this quantitative measurement using ambulatory urodynamic equipment.Patient concerns:A 49-year-old woman presented to our hospital with intermittent urine leakage. Five pads were used daily to keep the vulva dry. The preoperative urethral pressure profilometry (UPP) showed that maximum urethral pressure (MUP) was 54 cmH2O and maximum urethral closure pressure (MUCP) was 53 cmH2O.Diagnosis:According to the medical history and examination findings, the patient was diagnosed as SUI.Interventions:The MUS and UPP were performed.Outcomes:The intraoperative UPP showed that MUP was 29 cmH2O and MUCP was 17 cmH2O. Three months after the operation, the patient was followed up by telephone. The amount of urine pad usage decreased from 5 pads/d to 0 pads/d, reaching the social control standard (0–1 pads/d). The patient's international consultation on incontinence questionnaire short form score decreased from 18 to 5, and their incontinence quality of life score increased from 12.5 to 78.4. The effect of urine control was satisfactory, and no complications occurred.Five months after operation, the patient was reexamined in the outpatient department. The UPP showed that the MUP was 98 cmH2O and the MUCP was 72 cmH2O. The patient still uses 1 pad/day. The international consultation on incontinence questionnaire short form score is 6 and incontinence quality of life score is 79.5. The curative effect is stable.Lessons:MUS has become an effective surgical method for SUI, and the tightness of the sling directly affects the surgical outcome. We have achieved the measurement of urethral pressure during MUS. However, although we found that there is no obvious clinical significance of urethral pressure measurement in MUS operation, future research will benefit from our findings by improving upon our study design to help standardize the clinical diagnosis and treatment of MUS.

Objective: To explore the application of modified urethral separation method in artificial urethral sphincter (AUS) implantation in patients with stress urinary incontinence (SUI), and its influence on the results of urethral pressure profilometry. Methods: A prospective collection of clinical data was conducted on 25 patients with stress urinary incontinence who underwent modified urethral separation method in AUS implantation and underwent urethral pressure profilometry in Beijing Hospital, Beijing Jishuitan Hospital Affiliated to Capital Medical University and the Second Hospital Affiliated to Tianjin Medical University from March 2019 to June 2023. The improved urethral separation method was to borrow part of the white membrane tissue of the cavernous body while freeing the dorsal side of the cavernous body of the urethra. The circumference of the urethra, sleeve size, and urethral pressure were recorded, the patient's autonomous urinary control before and after surgery and the changes of the international consultation on incontinence questionnaire-short form (ICI-Q-SF) score, incontinence quality of life questionnaire (I-QoL) score, urinary frequency score, nocturia score were compared. Follow-up was conducted in the clinic or by telephone at 1, 3, 6, and 12 months after activation of the device, and once a year thereafter. Local skin status and urine control were assessed, residual urine volume was measured by ultrasound and subjective score scale was completed. Results: All patients were male, aged 27-85 (65.8±15.7) years old. The circumference of the cuff used in this study was 4.0 cm in 4 patients (16.0%), 4.5 cm in 16 patients (64.0%), 5.0 cm in 4 patients (16.0%), and 5.5 cm in 1 patient (4.0%). Among them, the urethral circumference matched the cuff size in 14 cases (56.0%), the urethral circumference was smaller than the cuff size in 4 cases (16.0%), and the urethral circumference was larger than the cuff size in 7 cases (28.0%). Preoperative urodynamic examination showed that the maximum urethral pressure (MUP) was (78.0±25.9) cmH2O, (1 cmH2O=0.098 kPa) and the maximum urethral closure pressure (MUCP) was (53.4±26.6) cmH2O. The MUP of AUS device in the inactivated state was (88.0±26.5) cmH2O, which was not significantly higher than that before operation (P>0.05). The MUCP was (68.2±24.5) cmH2O, which was significantly higher than that before operation (P<0.05). The MUP and MUCP of the AUS device in the activated state were (146.6±25.2) cmH2O and (123.0±28.3) cmH2O, which were significantly higher than those before surgery and in the inactivated state (both P<0.001). All patients in the group reached the social urinary control standards at the first month of device activation. During a follow-up period of 2-50 months, 22 patients (88.0%) used the initial AUS device and all met social urinary control standards. The AUS device was replaced in 1 case. One patient died of cerebrovascular accident. One patient removed the device due to complications. The number of pads [M (Q1, Q3)] used in 25 patients before and after operation was 4.5 (3.0, 6.5) and 1 (0, 1) respectively, with statistically significant differences (P<0.001). ICI-Q-SF score, I-QoL score, urinary frequency score and nocturia score of 25 patients were significantly improved after surgery (all P<0.05). The incidence of postoperative complications was 20.0% (5/25), including 2 cases of painless hematuria, 1 case of infection, 1 case of urethral erosion, and 1 case of dysuria. Except for one patient who experienced urethral erosion and had his sleeve removed, the remaining four patients regained social urination control with active support treatment, and no symptoms recurred until the last follow-up. Conclusion: The modified urethral separation method has no significant effect on urethral pressure in patients with SUI, and can increase the volume of peri-urethral tissue in the cuff, thereby reducing the risk of intraoperative urethral injury and the incidence of postoperative urethral erosion.

Objective To explore the clinical and urodynamic features of pelvic organ prolapse (POP) and its relationship with stress urinary incontinence (SUI). Methods From January 2003 to December 2006, 108 cases of perimenopausal and postmenopausal women, hospitalized in the Department of Obstetrics and Gynecology, GongLi Hospital, were admitted with stress urinary incontinence or pelvic organ prolapse surgeries, who had the urodynamic test aimed to evaluate prolapse based on the pelvic organ prolapse quantification (POP-Q) system, including the test of abdominal leak point pressure (ALPP), functional urethral length (FUL), maximal urethral closure pressure (MUCP), and maximal urethral pressure (MUP). Informed consent was obtained from all the participates. Results Among pelvic organ prolapse patients, stress urinary incontinence cases accounted for 68.5% (74/108). In terms of abdominal leak point pressure, the positive rate was 71.4% (70/98) in the pelvic organ prolapse patients who had participated in the urodynamic test. For functional urethral length, maximal urethral pressure, and maximal urethral closure pressure, significant decrease was identified in patients with pelvic organ prolapse. As to the abdominal leak point pressure among patients with and without stress urinary incontinence, the positive rates were 87.1% and 32.1%, respectively. In patients with uterine prolapse, the abdominal leak point pressure significantly increased over others. Taken of pressures at the abdominal leak point to evaluate, the incidence of occult stress urinary incontinence in pelvic organ prolapse patients would be 9.2% (9/98). There was no statistical difference in functional urethral length, maximal urethral pressure, and maximal urethral closure pressure between patients with stress urinary incontinence or not(P>0.05). Conclusion It is necessary to carry out preventive stress urinary incontinence correction operation for pelvic organ prolapse patients without clinical symptoms of stress urinary incontinence, in the condition of shorter functional urethral length, low maximal urethral closure pressure, and maximal urethral pressure value. Key words: pelvic organ prolapse (POP); stress urinary incontinence(SUI); abdominal leak point pressure(ALPP); functional urethral length (FUL); maximal urethral pressure(MUP); maximal urethral closure pressure(MUCP)

Objective: To investigate the changes of maximum urethral pressure (MUP) and maximum urethral closure pressure (MUCP) after artificial urethral sphincter (AUS) implantation and their prognostic value. Methods: The clinical data of patients who had undergone AUS implantation in multiple medical centers between March and July 2019 were retrospectively analyzed. Data of urethral pressure profilometry, pad usage, related scores and complications related to surgery were collected and compared. The primary endpoint was social continence (defined as 0-1 pad/d) 1 month after activation of the pump. Results: A total of five male patients were included in this study. Two underwent transurethral resection of the prostate for benign prostatic hyperplasia, two underwent radical prostatectomy for prostate cancer, and one underwent urethral reunion, urethral stricture dilatation and cystostomy due to trauma from traffic accident. All patients had different degrees of urinary incontinence. The results of preoperative urethral profilometry test showed that the MUP of five patients were 52, 53, 88, 32, and 66 cmH(2)O(1 cmH(2)O=0.098 kPa), respectively, and the MUCP were 17, 52, 62, 27, and 40 cmH(2)O, respectively. AUS implantation was performed. The intraoperative urethral pressure profilometry showed that the MUP were 53, 113, 50, 77, and 89 cmH(2)O in the inactivated state, and the MUCP were 50, 97, 31, 71, and 51 cmH(2)O, respectively. In the activated state, the MUP were 112, 174, 193, 121, and 120 cmH(2)O, and the MUCP were 109, 160, 175, 114, and 92 cmH(2)O, respectively. All patients met the social continence (0-1 pad/d) criterion. No complications were reported during the follow-up. Conclusions: The relationship between the range of intraoperative urethral pressure and the effect of urinary control can be gained by measuring the specific values of MUP and MUCP during AUS implantation and the post-operative effects, which provides as a data basis for standardizing AUS implantation.

BACKGROUNDArtificial urethral sphincter (AUS) implantation is currently the gold standard for treating moderate and severe urinary incontinence. Currently, cuffs are chosen based on the surgeon’s experience, and adjusting cuff tightness is crucial. The T-DOC air-charged catheter has not been proven to be inferior to traditional catheters. We report how intraoperative urethral pressure profilometry is performed using a T-DOC air-charged catheter with ambulatory urodynamic equipment, to guide cuff selection and adjustment.CASE SUMMARYA 67-year-old man presented to our hospital with complete urinary incontinence following transurethral prostatectomy, using five pads/d to maintain local dryness. Preoperatively, the maximum urethral pressure (MUP) and maximum urethral closure pressure (MUCP) were 52 cmH2O and 17 cmH2O, respectively. An AUS was implanted. Intraoperatively, in the inactivated state, the MUP and MUCP were 53 cmH2O and 50 cmH2O, respectively; in the activated state, they were 112 cmH2O and 109 cmH2O, respectively. The pump was activated 6 wk postoperatively. Re-measurement of the urethral pressure on the same day showed that in the inactivated state, MUP and MUCP were 89 cmH2O and 51 cmH2O, respectively, and in the activated state, 120 cmH2O and 92 cmH2O, respectively. One month after device activation, telephonic follow-up revealed that pad use had decreased from five pads/d to one pad/d, which met the standard for social continence (0-1 pad per day). There were no complications.CONCLUSIONThe relationship between intraoperative urethral pressure and urinary continence post-surgery can provide data for standardizing AUS implantation and evaluating efficacy.

The Relationships of Urethral and Pelvic Floor Muscles and the Urethral Pressure Measurements in Women with Stress Urinary Incontinence

Purpose: Patients with stress urinary incontinence at low urethral closure pressure, defined as maximum closure pressure equal or lower than 20 cm H 2 O, are at a higher risk for failure of surgical intervention. The aim of the study was to evaluate the objective healing and the changes of the urethral closure pressure of such women with severe urinary stress incontinence at hypotone urethra undergoing tension-free vaginal tape procedure. Material and Methods: Out of 150 patients who underwent TVT procedure between May 1999 and August 2000 because of urinary stress incontinence we found 29 of them with hypotone urethra. 25 of these were followed up in this study. Condition for enclosure was a positive stress test (leakage of urine like a jet at filled bladder with 300 ml while coughing as well in lying as in standing position) and a maximum urethral closure pressure lower or equal to 20cm H 2 O 4-6 weeks before surgery while performing urodynamic examination. 7 (4-12) months after surgery urodynamics and stress test were repeated. Healing was defined as negative stress test and regular maximum urethral pressure (higher than 20 cm H 2 O) at the time of control. Results: 19 (76%) patients had a negative stress test and a regular urethral pressure. At 4 (16%) women we found a negative stress test and still a hypotone urethra although maximum urethral pressure had risen but not up to 20 cm H 2 O. One (4%) patient still had a positive stress test with regular urethral closure pressure and one (4%) patient had a positive stress test as well as a hypotone urethra. Over all 23 (92%) patients had a negative stress test and were healed of urinary stress incontinence in all day situation. Conclusion: Our dates confirm TVT as a minimal invasive procedure to cure urinary stress incontinence in women with low pressure of the urethra.

Summary Urethral pressures profiles (upp) obtained by use of microtransducer catheters were determined in 8 anestrous sexually intact female Beagles during general anesthesia. A upp study consisted of 3 consecutive recordings, and 4 upp studies were repeated at an interval of 5 days in each dog. Maximal urethral pressure (cm of H2O), bladder pressure (cm of H2O), and anatomic urethral length (cm) were recorded. Maximal urethral closure pressure (cm of H2O) was calculated. Mean ± sd (for all measurements) maximal urethral closure pressure was 12.8 ± 5.6 cm of H2O (range, 2.4 to 25.2 cm of H2O). Maximal urethral closure pressure was significantly (P &lt; 0.05) decreased during the first recording period (11.4 ± 5.8 cm of H2O), compared with the second (13.0 ± 5.2 cm of H2O) or third (14.1 ± 5.7 cm of H2O) recording periods within a upp study (3 consecutive recordings). Mean maximal difference in urethral closure pressure during a single upp study was 4.8 ± 2.4 cm of H2O. Significant difference in maximal urethral closure pressure was not observed between studies. Mean (for all measurements) anatomic urethral length was 6.2 ± 0.9 cm (4.1 to 7.8 cm). Anatomic urethral length was significantly (P &lt; 0.05) less during the first recording period (6.1 ± 0.9 cm), compared with values for the second and third periods (6.3 ± 0.9cm, 6.4 ± 0.9 cm respectively). Anatomic urethral length for time 3 was significantly (P &lt; 0.05) less than the value for time 1 (5.8 ± 0.7 cm vs 6.6 ± 0.8 cm). We conclude that the microtransducer catheter technique for measurement of upp was reproducible during a single study and between successive studies. This method is useful in documenting maximal urethral pressure, maximal urethral closure pressure, and anatomic urethral length in clinically normal sexually intact female dogs.

Relevance of Detrusor Hyperreflexia, Vesical Compliance and Urethral Pressure to The Occurrence of Vesicoureteral Reflux in Myelodysplastic Patients

To compare urethral pressure reflectometry (UPR), a new and simple technique for simultaneous measurements of cross-sectional area (CA) and pressure in the female urethra, with urethral pressure profilometry (UPP). The study included 143 women (105 patients and 38 healthy volunteers); the UPR was measured using a very thin polyurethane bag in the urethra; a pump applied pre-selected pressures stepwise to the bag and for each step the CA was measured by acoustic reflectometry. Measurements were made during both inflation and deflation. The women were examined supine both while relaxed and during 'squeeze', and while upright and relaxed. The following variables were measured; the opening and closing pressure, the opening and closing elastance and the hysteresis. For UPP we used the perfusion technique with the patient supine and relaxed. All the women were assessed twice with both UPR and UPP at the same setting (short-term reproducibility) and 17 patients were assessed with both methods on two different days (long-term reproducibility). The mean pressures were 51.7 and 52.9 cmH(2)O for the UPR and UPP, respectively (not significant) at a CA of 5.1 mm(2); the limit of agreement between the methods was -19.4 to +17.0 cmH(2)O (mean and 2 SD). The Pearson coefficient was - 0.16 (not significant). The variability (2 sd) of two consecutive measurements was significantly less with UPR (9.5 cmH(2)O) than UPP (13.8 cmH(2)O; P < 0.001). For the opening and closing pressures the coefficient of variation (CV) was 5.9-11.6%; for the elastances the CV was 14.3-31.2% and for the hysteresis the CV was 12.9-49.1%. In test-retest measurements, the variability of the UPR values (2 sd, 8.7 cmH(2)O) was significantly less than for UPP (15.4 cmH(2)O; P < 0.05). The discomfort of UPR was statistically less than for UPP or than a standard gynaecological examination. Compared at the same CA, UPR measured the same pressure as UPP but the UPR was more reproducible. With the patient relaxed the opening and closing pressure, opening and closing elastance and the hysteresis can be measured while supine and upright; while squeezing, the opening pressure and elastance can be measured.

Urethral instability is still evolving as a clinical entity. Using pressure variation of 15 cm water or more at the point of maximum urethral pressure (MUP), urethral pressure profilometry on patients referred for urodynamic assessment for lower urinary tract symptoms revealed urethral instability in 6.4% of 608 patients. The close association between urethral and detrusor instability was noted. Urethral instability appears to be a cause of frequency and urgency of micturition, and its presence increase the risk of urinary incontinence.

The present study evaluated real-time changes in urethral pressure during the storage phase using a rat model with stress urinary incontinence (SUI) induced by simulated multiple birth traumas and investigated the relationship between urethral continence function and dynamic parameters associated with the changes in urethral pressure. Sprague-Dawley rats were divided into the following two groups: the sham group, which underwent three catheterizations of the vagina without distension at 2-wk intervals, and the vaginal distension (VD) group, which underwent three VDs at 2-wk intervals. After transection of the T8-T9 spinal cord, simultaneous bladder and urethral pressure recordings were performed during intravesical pressure elevation. Urodynamic parameters such as leak point pressure (LPP), urethral baseline pressure (UBP), maximum urethral pressure (MUP), the MUP-UBP differential (dUP) during intravesical pressure elevation, the bladder pressure when urethral contraction begins (Puc), and the bladder pressure at bladder neck opening (Pno) were then measured and compared. Compared with the sham group, LPP, UBP, dUP, MUP, Puc, and Pno were significantly decreased in the VD group. Pressure differences between LPP and Pno and between LPP and UBP (LPP-UBP) were also significantly different in the two groups. However, difference values of LPP and MUP or Pno and UBP were not altered after VD. Our new methods of simultaneous recordings of dynamic changes in bladder and urethral pressures are useful to fully evaluate the functional alterations in urethral continence function in the SUI model induced by multiple VDs. Moreover, LPP-UBP values, which correspond to the difference between Valsalva LPP and maximum urethral closure pressure in clinical urodynamics, would be useful to evaluate the impaired urethral continence function after simulated birth traumas in animal models.

This study investigated the relationship between abdominal obesity and stress urinary incontinence in Korean women. Women aged 30 and over, who visited the Department of Family Medicine of Asan Medical Center were recruited to participate in this study. Anthropometric measurements including body mass index (BMI) and waist circumference were taken, and associated factors of stress urinary incontinence was assessed by questionnaire. Stress urinary incontinence was significantly associated with physical work, vaginal delivery, and high waist circumference. In comparison with women in the lowest quartile of waist circumference, the odds ratios (OR) for stress urinary incontinence in women in the second, third, and fourth quartiles were increased significantly (1.79, 95% CI 1.07-2.98; 3.50, 95% CI 2.02-6.07; and 6.07, 95% CI 3.23-11.40, respectively). Our results indicate that high waist circumference may be a risk factor associated with stress urinary incontinence in women.

Dear Editor, I am very pleased that Dr. Peter Petros has taken the time to analyze and criticize the urethral hanging theory (UHT).1 However, with all due respect, I believe Dr. Petros has read the UHT articles hastily and has misunderstood many important points. Dr. Petros accentuates that challenging of a theory, is subject to the correct interpretation of original scientific proofs and Popper's rule to “better explain” predictions. I am aware of this, and in recent years, I have spent considerable time searching databases for evidence that contradicts the UHT. However, rather than discovering weaknesses and flaws, I have identified reports and studies that support the theory. Therefore, the criticism from Dr. Petros is very welcome. Dr. Petros lists five allegedly inaccurate statements (1-5) made by me and identifies two important questions for the UHT to address (6 and 7). Before I deal with these seven issues, I will comment on the three other statements made by Dr. Petros. Petros: “The UHT relies on abdominal pressure acting on the bladder to physically open out (“funnel”) the urethra.” This statement indicates a major misreading of the UHT.2 A central principle of the UHT is that a closed miniscule meatus internus (m.i.) is a perfect seal that cannot be pushed open by the intravesical pressure (IVP). There must be a pulling force that shears open/funnels the proximal urethra. The IVP is always perpendicular to the bladder wall and generates no shear forces to allow expansion of the m.i. This is in accordance with the law of elastic collision, meaning that a molecule bouncing against the bladder wall generates a force perpendicular to it. The bladder will rupture before it is opened. This is consistent with the findings of the study by Bush,3 which is referenced by Dr. Petros “where abdominal pressure two orders of magnitude (100 times) greater would be required to forcibly funnel the urethra”. Petros: “..the posterior urethra opens out concomitantly with depression of the anterior and posterior vaginal walls, and that this can only be explained by muscle action.” This statement is undeniably incorrect because urethral hanging in the bladder is another possible explanation. The 6th edition of the ICS Book4 describes the opening of the proximal urethra during stress. The occurrence of shearing/funneling can be observed using dynamic ultrasound. The reported description is said to support the integral theory (IT). However, it is also an excellent description of what happens when the proximal urethra is arrested and funneled by hanging from a filled bladder (UHT). The muscle actions that explain the open out the proximal urethra are the same muscle actions which generate the acutely high intra-abdominal pressure (Pabd) during stress. During normal micturition, the combined action of the inner longitudinal smooth muscles of the detrusor and urethra opens out the proximal urethra [2]. Petros: “.. nor can UHT explain how supporting the PUL with a hemostat applied to one side of the urethra can prevent funneling and restore geometry and continence with no elevation.” This statement is incorrect. According to the UHT, the hemostat prevents the urethra from descending and reaching a hanging/funneling position. However, there are women with stress urinary incontinence (SUI), in whom a hemostat with no elevation does not prevent funneling. These women have a hypomobile “fixed” urethra that is hanging/funneling even at rest. To prevent such hanging, the proximal urethra must be elevated above its resting position.5 In 2003, Petros reported about a clinical experiment using two types of virtual-operation (VO) techniques,6 which are as follows: the hemostat test (HT) described above and a pinch test (PT), which involves a one-sided fold of the suburethral vagina. Such a folding/tightening maneuver unavoidably results in shortening of the vaginal hammock, thereby causing a small elevation. Therefore, HT provides support with no elevation, whereas PT provides support with elevation. In other words, HT prevents urethral hanging/funneling in hypermobile SUI, whereas PT prevents it in both hypermobile and hypomobile SUI. From the viewpoint of the UHT, I regard HT as a test of the appropriateness of using tension-free suburethral tape (TVT) and PT as a test of the appropriateness of a lifting support. The two tests differentiate between hypermobile and hypomobile SUI. UHT uses the “therapeutic window” concept to differentiate and to choose the most appropriate procedure.7 Conversely, IT explains the impact of the VO techniques differently and proposes that HT supports the pubourethral ligaments (PUL), which kink, stretch, and narrow the proximal urethra, rather than being funneled when the posterior urethral wall is pulled down like a trapdoor, shearing it from the better supported anterior urethral wall. On the other hand, the PT is proposed to increase the contractile activity of the horseshoe-shaped rhabdosphincter (RS), because the pinching maneuver improves its insertion points in the vaginal wall.6 Petros reports, “Up to 20% to 30% of patients require tightening of the hammock (‘pinch test’) in addition to a midurethral anchoring to control urine loss on coughing when tested with ‘simulated operations’”.8 The UHT suggests that most of these women have hypomobile SUI. To create a lift without the risk of obstruction, the surgeon can use the “TVT technique” to insert one tuned tape in the paraurethral tissue on each side of the v.p.7 The comments/responses to the seven issues mentioned above are as follow. Issue 1. “The IT always postulated a tape at mid urethra, never 1 cm from external meatus!” Comment: Articles by Dr. Ulf Ulmsten, the co-originator of IT and the inventor of TVT, suggest another view. In 1996, Ulmsten stipulated an incision at the midline of the suburethral vaginal wall, starting approximately 0.5 cm from the outer urethral meatus.9 This was later changed to 1 cm10 and currently Ethicon (Gynecare TVT, US, LLC) stipulates a sagittal incision starting approximately 1.0 cm cephalad from the urethral meatus. In women with a short urethra (3 cm), an incision starting at 1 cm from the external meatus (m.e.) results in a midurethral tape position. However, in the case of a long urethra, such an incision results in a distal tape position [5]. Dr. Petros uses the term “mid-urethra”, but what position does that describe? Is it the middle of the anatomical urethra, the functional urethra, or the intra-abdominal urethra? Dr. DeLancey specified in 1986 that the approximate location of the intramural urethra is 0% to 20% of the anatomical urethral length and that of the mid urethra is 20% to 60%. This means that, in his opinion, the mid urethra ranges from the bladder neck to 60%.11 The UHT avoids the problems associated with different urethral lengths by stipulating that the tape should be inserted starting at 1 cm from the bladder neck. It could be conjectured that, because a short urethra has a foreshortened extra-abdominal part, the posterior PUL attachment to the vaginal wall is located at approximately the same distance from the bladder neck and at the midpoint of the intra-abdominal urethra. According to the UHT, a tape inserted at 1 cm from the meatus externus is, in the case of a short urethra (3 cm), curative for SUI with no postoperative urgency/frequency symptoms (OAB), and, in the case of a long urethra, curative for SUI but with a high risk of OAB. In a woman with a hypomobile urethra, it is infrequently curative for SUI and has a high risk of OAB. If the tape is set tension-free with no urethral obstruction, the UHT postulates that the OAB is the result of persistent funneling at rest and/or during stress.5 Issue 2. “The cause of urinary stress incontinence (USI) was never “multifactorial.” The IT always postulated USI was caused by a lax pubourethral ligament (PUL) inactivating two separate closure mechanisms, bladder neck, and distal urethra, Figure 1” Comment: Dr. Ulmsten had a different view: “Considering the multifactorial etiology and pathophysiology of female stress urinary incontinence, as well as the complicated integration of the anatomical structures involved in maintaining continence one must realize that no method can be expected to cure all patients.9 Issue 3. “The IT considers a loose PUL extension into pubococcygeus muscle as key to USI causation!” Comment: The UHT has the same consideration.12 However, there is a major difference between the two theories. The IT postulates that PUL act as a fulcrum promoting downward kinking of the proximal urethra, whereas the UHT postulates that the PUL act as a backstop2, 5, 7 that prevents the descent of the proximal urethra. Issue 4. “Dr. Bergström incorrectly states” In cases with hypomobile SUI, the proximal urethra should be lifted above its resting position.” (Quoting Zacharin who never provided radiological proof for this statement). No elevation postoperatively was demonstrated in all 30 prototype TVT patients!” Comment: I quoted Dr. Zacharin because he stipulates that “urinary continence control … is affected by … upper urethral anatomy on each side … and for a technique to be successful it must exert its influence at this precise point.13 This “precise point” proposed by Zacharin corresponds exactly with the vaginal point (v.p.) stipulated by the UHT. I did not quote Zacharin regarding the presence or absence of lifting. Issue 5. Dr Bergström incorrectly states “In the IT, the high pressure midurethral zone is flow-controlling.” The two closure mechanisms work by narrowing the urethra to exponentially increase resistance to flow and to close bladder neck by a kinking mechanism, or as originally described “like a ball valve” Comment: The flow-controlling zone is by definition the zone that prevents urine from entering the urethra. This zone can only be the m.i. An open m.i. results in a funneled bladder neck with urine in the proximal urethra, which is not normal and may trigger urgency/frequency symptoms. According to UHT, a closed miniscule m.i. is a perfect seal and is the flow-controlling zone. The RS and other striated muscles engaging the urethra form a secondary closure mechanism and are important for voluntary interruption of flow, emptying the urethra after micturition, and obstructing retrograde flow during activities such as swimming. Closure of the proximal urethra is affected by its intrinsic muscles and vascular plexus, but not at least, by its rich content of collagen and elastic fibers. The IT emphasizes urethral resistance to flow. According to IT, three directional muscles kink, stretch, and narrow the proximal urethra with the midurethral PUL as a fulcrum. The resistance to flow in the proximal urethra increases/decreases inversely to its radius, as defined by the Hagen-Poiseuille law. This control of urethral resistance results in the control of closure and emptying.8 Moreover, the IT underlines the importance of the striated RS.14, 15 A lax anterior vaginal wall is said to result in a suboptimal RS muscle length; therefore, it does not have optimal muscle strength, which will reduce its ability to contract and increase the urethral resistance.8 In 2015, Dr. Petros postulated that “… whether a patient leaks urine or not has nothing to do with pressure, it is to do with musculoelastic closure of the urethral tube and … narrowing the urethral diameter by the external striated muscle closure mechanism…exponentially raising the resistance to flow.16 Nevertheless, why this prevailing major interest in the urethral resistance to flow? In fact, it does not matter whether the resistance is high or low; the IVP is independent of the conditions behind a closed m.i. A pulling/shearing force is required to open the m.i., and this force does not depend on the level of urethral resistance. Dr. Petros pays attention to a “ball valve” mechanism, wherein the bladder rotates around the insertion point of a pubovesical ligament to close the bladder neck.8 Such mechanism has seldom been suggested. Issue 6. How does UHT explain continence restoration with a skin graft in Obstetric Fistula patients? Response: If the women who were successfully treated had SUI, they were cured because their urethra was reconstructed and then supported by a suburethral Singapore flap and a sling. The flap and sling prevent the urethra from descending and reaching a hanging position.17 Issue 7. How does UHT explain an increase in urethral pressure 0.25 seconds before a cough and higher urethral than bladder pressure during, if everything is done by “pressure transmission?” Response: To cough, the woman has to produce an acutely high Pabd. Such pressure increase is created by simultaneously contracting all the muscles surrounding the abdominal cavity (AC), including the diaphragm and the pelvic floor muscles (PFM). A key element in continence is the attachment of the endopelvic fascia to the levator ani muscles on both sides at the arcus tendineus fascia pelvis.18 Contraction of the PFM elevates the vaginal wall and forces the posterior urethral wall against the anterior urethral wall. The striated RS has the same somatic innervation as the PFM (S2-S4) and contracts in synchrony with them. These synchronized contractions can also be defined as guarding reflexes (GR). Predictably, to produce a cough, muscle contractions must start before the cough; hence, the urethral pressure (UP) begins to increase before the cough. The proximal urethra is situated intra-abdominally, and consequently the Pabd “transmission” is 100%. At the time of a cough, UP = MUP + GR + Pabd > IVP, where MUP = maximum urethral pressure at rest. Thus, the increase in UP to levels higher than the bladder pressure begins before the cough. Coughing (short valsalva) indicates the presence of large GR forces because the intention is to expell something out of the mouth. Strain—correctly performed—means little GR forces because the intention is to let something out from the bottom, which is facilitated by relaxation of the pelvic floor. Finally, Dr Petros argues that the UHT cannot explain the ultrasound events shown in Figure 1 of his article, and states that there is “No indentation of the anterior bladder wall, a prerequisite if intra-abdominal pressure is to cause funneling; the anterior urethral wall remains in situ.” Comment: This is a surprising argument. The UHT means exactly what the name suggests. Figure 1.2 shows a hanging urethra.1 The Pabd is the cause of the hanging situation. Perhaps Dr. Petros does not perceive this because the originators of the IT rejected the theory of direct abdominal pressure transmission.14,15 However, I find Figure 1.5 incomprehensible. In the case of a woman who has loose and lengthened PUL, the urethra is pictured as an upwards bow. This is inconsistent with Figure 1.2, which shows the reverse. I explain below my view of how Pabd affects hanging/forced funneling. The AC is a closed entity and similar to a water bag. All but 10%-15% of its content is incompressible water with some gas. The Pabd is the same throughout the cavity, except for a hydrostatic pressure component. Therefore, in a closed entity like the AC, a change in Pabd affects the whole cavity simultaneously. This is in accordance with Pascal's law of fluid pressures, which states that when there is an increase in pressure at any point in a confined fluid, there is an equal increase at every other point in the container. Enhörning's direct abdominal pressure transmission theory (ET),19 is grounded on this pressure law although ET is not correct regarding the lower limit of the AC.2 During straining, the pressure increases concurrently throughout the entire AC. The same pressure increase occurs around/inside the bladder and around/inside the proximal urethra. There is no compression of the abdominal contents and everything stays in approximately the same position. This is a zero-sum situation even though the pressure is higher. If a woman is continent at rest, she is also continent under stress. An exception to this situation is when the AC is asymmetrically deformed, which is the case in SUI. The urethra and bladder base are both fixed to the endopelvic fascia/anterior vaginal wall but at different points; the urethra is fixed more distally than the bladder base. If the endopelvic fascia (pubocervical fascia) beneath the proximal urethra is defective, and the fascia beneath the bladder base is not, the urethra will descend relative to the bladder and reach a hanging position that generates a pulling/shearing force that funnels the proximal urethra. This, in a nutshell, is the UHT (Figure 1). Hypermobile SUI during a valsalva maneuver. The long urethra (4.5 cm) is “wheeling” downward, hanging in between the anterior PUL and bladder. Funneling at Pabd < aLPP. According to Pascal's formula Fd = (Pabd + Pdet) × π × r2. MUP+GR+Pabd resists the Fs/Fd. The intermediate PUL are not attached to the os pubis. Between that part of the PUL and os pubis, there is only fat and the v. clitoridis. The IT stipulates a suburethral tape that starts at 1 cm from the m.e. The UHT stipulates a suburethral tape that starts at 1 cm from the bladder neck, that is, center of tape at v.p. The figure can alternatively be said to demonstrate a urethra with very small mobility (“fixed urethra”), hanging/funneling even at rest. In such severe hypomobile SUI, a suburethral tension-free tape is of marginal, if any, benefit to the woman. To stop hanging, the proximal urethra at v.p., must accordingly be lifted above its resting position. Abbreviations: aLPP, abdominal leak point pressure; Fd, outflow distending force; Fs, shearing forces; IT, The integral theory; m.e., meatus externus; m.i., meatus internus; MUP, maximum urethral pressure at rest; Pabd, intra-abdominal pressure; PCF, pubo-coccygeal fascia; Pdet, detrusor pressure; PUL, pubourethral ligaments; r, radius of m.i.; SUI, stress urinary incontinence; UHT, urethral hanging theory; v.p., vaginal point; GR, guarding reflex. However, besides better support, relative to the urethra, a full bladder is heavy with a resistance to acceleration (inertia). During cough the “light-weighted” unsupported urethra rapidly descents in contrast to a full bladder. This increases the risk for urethral hanging. A full bladder is also large and its ability to descend is restrained. In contrast to the UHT, the IT, rejecting ET, hypothesizes that the increase in UP during stress, is produced by the fast twitch contraction of the RS and by the kinking/stretching/narrowing action (KINK) of the muscles using PUL as a fulcrum. In the UHT, the PUL act as a backstop that sustains the correct spatial relationship between the proximal urethra and the bladder, thereby preventing the urethra from reaching a hanging position. A closed m.i. has, per definition, a zero or an almost zero radius and accordingly, the outflow distending force (Fd) will be zero or minimal (Fd = IVP × π × r2). This is analogous to blowing up a rubber balloon, where the initiation of expansion may be nearly impossible without first manually dilating the mouthpiece (“radius”). Thus, there must be a force that pulls open the m.i.—a high IVP cannot push it open. ICS defines genuine stress incontinence as “involuntary urethral loss of urine when the IVP exceeds the maximum UP in the absence of detrusor activity.” Is it time to change this definition? The so-called intrinsic sphincter deficiency (ISD) type of SUI, also called type III SUI, in which the fixed “stovepipe” urethra, low maximum urethral closure pressure at rest and funneling at rest, is, according to the UHT, nothing less than a urethra that is hanging/funneling even at rest. ISD is often described as a form of SUI with a week sphincter and good support. In viewpoint of the UHT the “week sphincter” is the forced funneling of the proximal urethra and the “good support” is the urethra tethered to a less mobile bladder, limiting its descent. Women with “ISD” frequently have severe urgency/frequency symptoms due to the hanging/funneling position even at rest and to situations wherein only a small stressful event causes the Pabd to reach the abdominal leak point pressure (aLPP). Restoration of the defective suburethral support immediately corrects the supposed intrinsic urethral defect, which demonstrates that it has a functional, not a morphological cause. According to the UHT, SUI, and mixed urinary incontinence (MUI) are the same disease. Approximately 80% to 90% of cases of SUI are hypermobile SUI, which have high success rates almost irrespective of the TVT position, whereas 10% to 20% are hypomobile SUI, which have a high failure rate for surgery. TVT surgery has an overall failure rate of 10% to 20%, and many women cured of SUI have de novo or persistent symptoms of urgency/frequency. About one-third of all surgical procedures for SUI are performed in women with recurrent SUI and are unfortunately associated with worse outcomes than in case of a primary surgery. As life expectancy is expected to increase, management of recurrent SUI will be an increasing problem until a better understanding of SUI surgery failure is provided. There has been no change in the rates of failure and adverse events since the introduction of TVT almost 25 years ago. “It appears that we have reached a ceiling in and As a we have not been to a rather high rate of and expected must be (Figure It should be that the for TVT is on the In the originators of IT has been very little in the surgery of female urinary incontinence the In this is due to of the pressure transmission in a of his Dr. and his theory “… it is not possible to that kinking could be the mechanism the urethra I with and that the of ET, as well as the of IT, in almost 30 years, a correct understanding of SUI. The Dr. in at the of years Abbreviations: UHT, urethral theory; IT, integral theory; ET, theory; PUL, ligaments; IVP, intravesical pressure; Pdet, detrusor pressure; MUP, maximum urethral pressure at rest; urethral pressure; Pabd, pressure; Fs, shearing force; Fd, outflow distending force; kinking/stretching/narrowing of the proximal urethra against the PUL as a muscles the vaginal and the posterior urethra wall against its anterior rhabdosphincter according to IT, both RS and have in cases of loose and lengthened GR, guarding reflexes = Enhörning's pressure transmission theory is incorrect regarding the lower limit of the abdominal cavity but is The UHT suggests that there is a between the two types of SUI, and In the on of in the 6th edition ICS the that is a for a which would these regarding and and patients with stress incontinence urethral though it is not what it is about that mobility which urethral opening during I that these two are by the UHT. The of women who SUI surgery are A the and is a for the woman. It is that SUI higher success The UHT is a for understanding the pathophysiology of female urinary