Detrusor-myoplasty,innervated rectus muscle transposition study,and functional effect on the spinal cord injury rat model

The purpose of this investigation was to determine the feasibility of striated muscular augmentation of the urinary bladder (detrusor-myoplasty, DMP). Initial studies, transposition, and bladder wrap using several distinct muscle groups was attempted in laboratory rats, goats, and fresh human cadavers. The rectus abdominus muscle was found to be best suited to completely encompass the bladder with an intact neural and vascular supply. The technique was then applied in a rat model of spinal cord injury (SCI). Modified Tarlov ratings were employed to assess neurologic function 30 days after SCI. The median final neurological score of SCI rats with and without DMP was 4 and 5, respectively. Sham-operated SCI (control) rats, with and without DMP, both had normal final Tarlov scores of 12 (P < 0.05). Muscle blood flow values for the flap and the contralateral undissected rectus muscles were not significantly different (97 ± 34 and 105 ± 40 ml/100 g tissue/min, respectively, P = 0.47). Postoperatively, no bowel or abdominal wall functional deficits were apparent. The rotated muscular flap remained innervated and vascularized. Analysis of 24 hr micturition patterns demonstrated no differences in oral fluid intake/24hr. voided volume/24hr, and ratio of number of micturitions during the night vs. day among the four groups: (1) control (neither SCI nor DMP), (2) DMP only, (3) SCI only, and (4) SCI with DMP. Spinal cord injured rats with and without detrusor-myoplasty demonstrated a significant decrease in the number of micturitions/24hr, an increased volume per micturition, and greater largest and smallest micturition volumes (P < 0.05) when compared to controls. The micturition patterns among SCI rats with and without DMP were similar, as were non-SCI animals with and without DMP. This is the first report of the principle and technique of detrusor-myoplasty. Dissection of rats, goats, and human cadavers revealed that a vascularized and innervated rectus muscle flap can be rotated into the pelvis and wrapped around the bladder without tension. Significant loss of bladder capacity did not occur with skeletal muscle adaptation. Detrusor-myoplasty may be applicable for patients with an areflexic detrusor and non-intact sacral motor roots who are not candidates for sacral anterior root neurostimulation. © 1994 Wiley-Liss, Inc.     

Partial outlet obstruction induces chronic distension and increased stiffness of rat urinary bladder

In order to identify the passive properties of the bladder during filling, we measured cystometrograms (CMGs) of rat urinary bladders that had been outlet obstructed for 6 weeks and age-matched controls in conscious, unrestrained animals and in fully relaxed whole bladders in an organ bath. In the organ bath, each bladder was allowed to empty passively at zero transmural pressure. The volume remaining was labelled zero pressure volume (ZPV) and was used as the reference volume to normalize contained volume, deriving wall stretch. Increased ZPV implies that the bladder contains more urine at low stresses and therefore is more distended. In awake animals, the obstructed bladder CMGs showed spontaneous contractions. The pressures between contractions were similar to those in CMGs performed in the organ bath, suggesting that passive properties determine the minimum pressures during filling in vivo. The ZPV of the obstructed and control bladders was 1.07 ± 0.12 ml and 0.07 ± 0.01 ml, respectively. The differences were significant (P < 0.01). The ZPV correlated with bladder weight and thus with degree of hypertrophy. Under conditions when weight cannot be determined, e.g., clinically, ZPV may provide a useful measure of the degree of chronic distension and bladder hypertrophy. The pressure-volume curves of the obstructed bladder CMGs in vitro varied between preparations. However, when pressure-volume was converted to stress-stretch using the law of Laplace, the obstructed bladders were all significantly stiffer than the controls. We confirmed this result by step-stretching relaxed bladder strips. The obstructed bladder strips again demonstrated stiffer stress-stretch curves than the controls. © Wiley-Liss, Inc.     

Effects of atropine on bladder capacity and instability in rats with bladder hypertrophy

Cystometries were performed in conscious normal rats and in rats with infravesical outflow obstruction in the absence and presence of atropine. The effects were evaluated with regard to bladder capacity, bladder compliance, threshold pressure, micturition volume, residual volume, micturition pressure, and spontaneous contractile activity. In control rats following the administration of atropine, bladder capacity increased in six of seven experiments, but this effect was not statistically significant. No other cystometrical variable was changed in control rats by muscarinic receptor blockade. Bladder capacity in obstructed rats was clearly larger than in control rats (mean 4.4 ± 1.1 and 0.20 ± 0.02 ml, respectively). In obstructed rats atropine significantly increased bladder capacity from 4.4 ± 1.1 to 7.9 ± 1.2 ml. Further, the obstructed rats were characterized by an increase in threshold pressure and residual volume, and a decrease in micturition volume after atropine administration. Micturition pressure in obstructed rats was higher than in control rats (131 ± 29 and 33 ± 6 cm H₂O, respectively). In obstructed rats, administration of atropine decreased micturition pressure, indicating a cholinergic component participating in bladder contraction. A clear-cut bladder instability was observed in all obstructed rats, and part of the contractions remained after atropine, suggesting a myogenic or a noncholinergic nervous origin.     

Autoaugmentation gastrocystoplasty: further studies of the sheep model

OBJECTIVE: To report our experience with autoaugmentation gastrocystoplasty (AAGC, reported to result in an inconsistent augmentation effect in children) in a sheep model, specifically addressing issues of surgical techniques and postoperative bladder drainage that may affect the augmentation result, as many factors have been implicated in the poor outcome. MATERIALS AND METHODS: Ten 6-month-old male lambs had a suprapubic catheter placed by an open laparotomy. Intraoperative urodynamics were evaluated before and after detrusorotomy for autoaugmentation and after completing AAGC. The bladder was drained with no distension for 1 week after surgery and the urodynamic evaluation repeated on control and experimental animals 6 months after surgery. The animals were then killed and the bladders evaluated for gastric flap survival and histological changes in the native bladder and augmentation segments. The results were analysed using a one-sided Student's t-test. RESULTS: The median (range) native bladder volume at leak-point pressure was 110 (40-490) mL. Intraoperative bladder volumes after completing AAGC confirmed adequate augmentation segments in all animals. The urodynamic evaluation at 6 months after AAGC showed increases in bladder volumes in nine of 10 animals (0-1336 mL), significantly greater than the increase in volume in the control sheep (median 337.5 vs 115.3 mL; P < 0.05). The bladder compliance (volume/pressure at leak capacity) 6 months after AAGC was slightly better but not significantly higher than in controls (median 17.3 vs 10.8 mL/cmH(2)O; P > 0.05). The median (range) ratio of surviving gastric flap to native bladder circumferences was 34.5 (31-53)%. Histology showed scarring of the submucosal layer in one of 10 augmentation segments and normal urothelium in all bladders. CONCLUSION: AAGC produces reliable bladder augmentation and excellent bladder compliance in a sheep model of a non-neurogenic bladder. The gastric flap survived well and there was no bladder wall separation with simple postoperative catheter drainage.     

Possible use of ultrasonically-estimated bladder weight in patients with neurogenic bladder dysfunction

In 25 patients with detrusor areflexia, ultrasonically-estimated bladder weight (UEBW) was compared with bladder capacity and compliance obtained by cystometry, and UEBW was also compared with grade of bladder deformity as evaluated by cystography. UEBW correlated significantly with compliance (P < 0.01) and degree of bladder deformity (P < 0.01). Taking a cutoff value of 40 g, UEBW revealed diagnostic accuracy as high as 96% and 80% for low-compliance (< 10 ml/cm H₂O) and high-grade deformity (grade II/III), respectively. UEBW could be a new urodynamic parameter capable of evaluating functional as well as morphological changes of the bladder. © 1996 Wiley-Liss, Inc.     

Increased bladder wall thickness is associated with severe symptoms and reduced bladder capacity in patients with bladder pain syndrome

ObjectivePatients with interstitial cystitis (IC) and ketamine cystitis (KC) usually have similar symptoms, such as frequency, urgency, and bladder pain. In patients with IC, ulcer type and nonulcer type may have different cystoscopic features. This study investigated the clinical characteristics and bladder wall thickness (BWT) measured using computed tomography (CT) in patients with nonulcer IC, ulcer IC, and KC.Materials and methodsThe detailed history and bladder condition of patients with a clinical diagnosis of IC and KC were retrospectively analyzed. An abdominal to pelvis CT scan with/without contrast was performed in every patient. Ulcer type IC was noted in nine patients, nonulcer IC in seven patients, and KC in 13 patients. The bladder mass volume and BWT were measured. Bladder CT images of 10 patients with nonmetastatic renal cancer served as controls.ResultsThe bladder wall was significantly thicker in all patients with ulcer type IC (8.91 ± 2.67 mm) and KC (10.7 ± 3.44 mm) than in those with nonulcer IC (2.89 ± 0.73 mm) or controls (2.65 ± 0.97 mm). Among KC patients, eight patients received augmentation enterocystoplasty. Moreover, the bladder wall was significantly thicker in patients who underwent augmentation enterocystoplasty (11.50 ± 3.21 mm) than those who did not (9.50 ± 3.81 mm). The bladder mass volume was increased in patients with KC who received augmentation enterocystoplasty (35.67 ± 11.19 mL) compared with those who did not (21.24 ± 7.25 mL). BWT significantly correlated with visual analogue scores for pain (R² = 0.484, p < 0.001), functional bladder capacity (R² = 0.31, p = 0.002), and maximum bladder capacity (R² = 0.469, p < 0.001) in overall patients.ConclusionThere are obvious differences in bladder CT scans of patients with symptoms of bladder pain due to different etiology. Increased BWT was associated with increased pain scores and decreased bladder capacity in patients with KC and IC. BWT on a CT scan might be considered a marker for the severity of bladder inflammation.     

In-Vivo Whole Bladder Response to Anticholinergic and Musculotropic Agents in Spinal Cord Injured Rats

Abstract

The purpose of this study was to compare the effect on urodynamic parameters of anticholinergic and musculotropic agents in sham injured and spinal cord injured (SC I) rats. A standard rat SCI model induced by impact trauma was employed. Cystometrograms were performed under urethane anesthesia four weeks after SCI. Bladder capacity and voiding pressure were determined at the point of micturition monitored urodynamically and visually. The effect of oxybutynin chloride (0.01 - 0.1 mg/kg), propantheline bromide (0.05 - 0.5 mg/kg) and flavoxate hydrochloride (0.1 - 1.0 mg/kg) were assessed independently in sham injured and SCI rats (n = 1 0 in each group). Bladder capacities were 0.6± 0.2 and 7.1± 1.6 ml in sham and SCI rats (p <0.01 ), respectively. Maximal filling pressure was 17.5±5 mmHg in sham and 25±5 mmHg in SCI rats (p <0.05). Bladder capacity increased with all three medications. Administration of oxybutynin, propantheline and flavoxate in sham rats resulted in bladder capacities of 0.88±0.3, 0.71±0.3 and 0.8± 0.2 ml, respectively (p <0.01 ). In SCI rats, these drugs resulted in bladder capacities of 9.8± 1.1, 7.9± 1.3 and 8.8±2.0 ml , respectively (p <0.01 ). No significant change in maximum filling pressure occurred. We conclude that anticholinergic and musculotropic agents caused a similar increase in bladder capacity in both sham and SCI rats. Oxybutynin enhanced bladder capacity more than propantheline or flavoxate. (J Spinal Cord Med 1997; 20:31-35)     

Baroreceptor-heart rate reflex sensitivity enhancement after urinary bladder distention in essential hypertensives

Our objective was to determine if urinary bladder distention modifies the sensitivity of the baroreceptor-heart rate reflex in hypertensive and control subjects. The baroreceptor-heart rate reflex sensitivity was measured in 15 male patients (mean age 37 ± 8 years) with mild untreated hypertension (mean 163 ± 8/95 ± 12 mmHg) and 17 age- and sex-matched control subjects before and after urinary bladder distention. Bladder filling was performed infusing saline heated to 37°C via a urinary catheter; the volume infused in each patient corresponded to that which caused the urge to void without reaching the pain threshold. The baroreceptor-heart rate reflex sensitivity was determined correlating the variations of the systolic pressure and of the peak blood flow velocity in the common carotid artery with the variations of the ECG RR′ interval of the following heart beat, both during spontaneous and phenylephrine-induced fluctuations of the haemodynamic variables. After bladder distention the diastolic pressure of the hypertensive subjects increased significantly (95 ± 12 vs. 100 ± 12 mmHg; P < 0.02), whereas the heart rate decreased (RR=873 ± 70 vs. 926 ± 80 ms; P < 0.005). These parameters were unchanged in the normotensive subjects (84 ± 9 vs. 83 ± 8 mmHg and 914 ± 158 vs. 913±140 ms, respectively). The baroreceptor-heart rate reflex sensitivity, measured on the basis of spontaneous pressure and carotid blood flow velocity fluctuations in relationship to RR changes, decreased in the normotensive subjects after bladder distention (10.7 ± 4.6 vs. 9.4 ± 2.7 ms/mmHg; P < 0.05 and 423 ± 99 vs. 356 ± 102 ms/kHz; P < 0.01, respectively), whereas it increased in the hypertensive patients (6.9 ± 3.6 vs. 8.3 ± 2.8 ms/mmHg; P < 0.03, and 332 ± 86 vs. 381 ± 97 ms/kHz; P < 0.03 respectively). After bladder distention and phenylephrine administration the baroreceptor-heart rate reflex sensitivity, measured by the correlation between systolic pressure and RR interval, increased only in the hypertensive group (10.2 ± 5.4 vs. 15.2 ± 7.7 ms/mmHg; P < 0.005). In conclusion urinary bladder distention provokes in hypertensives but not normotensive controls a brisk parasympathetic response of the component of the baroreceptor-heart rate reflex which controls heart rate. Received: 17 June 1998 / Accepted: 20 October 1998     

Post-augmentation bladder perforation during urodynamic investigation

AIMS: To report for the first time bladder rupture during filling cystometry many years after bladder augmentation. METHODS: A 17-year-old girl with T10 meningomyelocele had received an ileocystoplasty, continent catheterizable stoma, and bladder neck sling for neurogenic bladder dysfunction and intractable incontinence 8 years previously. She was continent with clean intermittent self-catheterization four times per day. Yearly urodynamics showed a bladder capacity of up to 700 ml with good compliance and low bladder pressures. In March 2006, filling cystometry was performed. RESULTS: Bladder pressure was normal until 400 ml, after which it increased due to lower compliance. At 620 ml filling, the detrusor pressure was 52 cm H2O, and the patient complained suddenly of abdominal discomfort and bilateral shoulder pain, and the infusion was stopped. A catheter was placed and cystography showed intraperitoneal leakage along the left lateral bladder aspect and at the Mitrofanoff insertion site on the bladder dome. The perforations were closed via a midline incision and a ventriculoperitoneal shunt had to be exteriorized. There were no post-operative complications and a control cystogram revealed no leakage. CONCLUSIONS: Augmentation ileocystoplasty has been used extensively in order to increase bladder capacity and decrease intravesical pressure. Although spontaneous or traumatic perforation of the augmented bladder has been described previously, it was never reported in correlation with urodynamic investigation. Extreme caution is warranted in the face of decreased compliance during filling cystometry in these patients, even though urodynamics showed good bladder compliance and low bladder pressures many years after ileocystoplasty.     

两种膀胱扩大术治疗神经源性膀胱比较分析

目的:比较膀胱自扩大术和回肠膀胱扩大术治疗神经源性膀胱的临床效果。方法:回顾分析膀胱自扩大术10例,回肠膀胱扩大术13例患者临床资料,对两种术式的手术方法,手术前后患者膀胱容量,肾功能以及临床症状进行比较。结果:膀胱自扩大术和回肠膀胱扩大术的患者术后平均安全膀胱容量显著增多,分别为(178.2±31.8)vs(420.7±54.9)ml,(115.9±19.5)vs(517.4±48.3)ml(P<0.05),顺应性明显改善。前者尿失禁消失8例,明显改善1例;术后血清肌酐水平恢复正常6例,明显下降2例,肾积水明显缓解或消失,未发现膀胱输尿管反流现象;后者尿失禁消失9例,明显改善2例,血清肌酐水平6例恢复正常,1例明显下降,肾积水情况均较术前明显缓解或消失,膀胱输尿管反流消失;术后3例出现尿路感染;1例轻微漏尿;1例出现腹泻;3例出现肠梗阻;2例出现膀胱结石,均对症处理后好转。结论:膀胱自扩大术较为简单、安全,但其适应证把握应慎重。回肠膀胱扩大术是治疗神经源性膀胱有效的手术方式,其适应证相对广,但并发症较多。     

Long-term complications following bladder augmentations in patients with spina bifida: bladder calculi,perforation of the augmented bladder and upper tract deterioration

Background

We desire to review our experience with bladder augmentation in spina bifida patients followed in a transitional and adult urologic practice. This paper will specifically focus on three major complications: bladder calculi, the most frequent complication found following bladder augmentation, perforation of the augmentation, its most lethal complication and finally we will address loss of renal function as a direct result of our surgical reconstructive procedures.

Methods

We reviewed a prospective data base maintained on patients with spina bifida followed in our transitional and adult urology clinic from 1986 to date. Specific attention was given to patients who had developed bladder calculi, sustained a spontaneous perforation of the augmented bladder or had developed new onset of renal scarring or renal insufficiency (≥ stage 3 renal failure) during prolonged follow-up.

Results

The development of renal stones (P<0.05) and symptomatic urinary tract infections (P<0.0001) were found to be significantly reduced by the use of high volume (≥240 mL) daily bladder wash outs. Individuals who still developed bladder calculi recalcitrant to high volume wash outs were not benefited by the correction of underlying metabolic abnormalities or mucolytic agents. Spontaneous bladder perforations in the adult patient population with spina bifida were found to be directly correlated to substance abuse and noncompliance with intermittent catheterization, P<0.005. Deterioration of the upper tracts as defined by the new onset of renal scars occurred in 40% (32/80) of the patients managed by a ileocystoplasty and simultaneous bladder neck outlet procedure during a median follow-up interval 14 years (range, 8–45 years). Development of ≥ stage 3 chronic renal failure occurred within 38% (12/32) of the patients with scarring i.e., 15% (12/80) of the total patient population. Prior to the development of the renal scarring, 69% (22/32) of the patients had been noncompliant with intermittent catheterization. The onset of upper tract deterioration (i.e., new scar formation, hydronephrosis, calculus development, decrease in renal function) was silent, that is, clinically asymptomatic in one third (10/32 pts).

Conclusions

This paper documents the need for high volume bladder irrigations to both prevent the most common complication following bladder augmentation, which is the development of bladder calculi and to reduce the incidence of symptomatic urinary tract infections. It provides a unique perspective regarding the impact of substance abuse and patient non-compliance with medical directives as being both the most common cause for both spontaneous bladder rupture following augmentation cystoplasty and for deterioration of the upper tracts. These findings should cause the surgeon to reflect on his/her assessment of a patient prior to performing a bladder augmentation procedure and stress the need for close follow-up.     

Effects of buffering in hypercapnia and hypercapnic hypoxemia

Anesthetized, paralyzed and mechanically ventilated pigs were exposed to extreme hypercapnia (Paco_2-20 kPa) at Fio₂ 0.4 for 480 min, with (n = 6) or without (n = 6) continuous infusion of isotonic buffers (bicarbonate and trometamol). Arterial pH was higher in buffered animals than controls, 7.21 ±0.01 vs 7.01±0.01 (mean ± s.e.mean, P < 0.01). Serum osmolality and Paco₂ did not differ between groups throughout the experiment. The hemodynamic response to hypercapnia was attenuated in the buffered group, who had lower heart rate, 133 ± 6 vs 189±12 min^-1 (P < 0.01), mean arterial pressure (MAP) 109 ± 4 vs 124 ± 4 mmHg (14.5 ± 0.5 vs 16.5 ± 0.5 kPa) (P < 0.05), mean pulmonary arterial pressure 16±1 vs 23 ± 1 mmHg (2.1 ±0.1 vs 3.1 ±0.1 kPa) (P < 0.01), and pulmonary vascular resistance (PVR) 249 ± 21 vs 343 ± 20 dyn s-cm^-5 (2490±210 vs 3430±200 μN-s-cm^-5) (P < 0.01), compared with the control group. Subsequently, both groups were exposed to hypercapnic hypoxemia by stepwise increases in Fio₂ (0.15, 0.10, 0.05) at 30-min intervals, while Fico₂ was kept at 0.2. PVR increased in both groups (P < 0.05) but, except for heart rate, all hemodynamic differences between the groups disappeared during hypoxia. At Fio₂ 0.15, buffered animals had higher arterial oxygen saturation (73 ± 5%) than the controls (55 ± 5%), (P < 0.05). The control animals died after 1–29 min (mean 14 min) at Fio₂ 0.10, while all buffered animals survived Fio₂ 0.10 with stable MAP (122 ± 14 mmHg (16.3 ± 1.9 kPa). The buffered animals died after 4–22 min (mean 15 min) at Fio₂ 0.05. We conclude that buffering to a pH of 7.21 attenuates the observed hemodynamic response in extreme hypercapnia and improves survival in hypercapnic hypoxemia.     

膀胱次全切除回肠扩大膀胱术治疗神经源性膀胱尿道功能障碍

目的：探讨肠道扩大膀胱成形术治疗神经源性膀胱尿道功能障碍的价值。方法：采用膀胱次全切除、回肠扩大膀胱成形术治疗7例神经源性膀胱尿道功能障碍患者。结果：2例术后排尿通畅，剩余尿消失；3例术后曾有排尿困难，经尿道膀胱颈电切后排尿通畅，无尿失禁，最大尿流率分别为27、16和18ml/s；1例术前曾采用经尿道膀胱颈电切术无效，行本手术后剩余尿消失，但仍有尿失禁，后在超声引导下于尿道周围注射硅酮后，尿失禁症状明显改善；余1例术后仍有排尿困难。结论：该手术方法对神经源性膀胱尿道功能障碍是一种可行的治疗方法。     

Comparative analysis of bladder wall compliance based on cystometry and biosensor measurements during the micturition cycle of the rat

The stiffness characteristics of the empty and filling bladder and the modulating influence of oxybutynin were investigated using a new biosensor system. Studies were done comparing the stiffness measured using the pressure/volume relationship with direct biosensor monitoring on male and female rats during isovolumetric contractions elicited during the cystometrogram (CMG). Bladder stiffness at zero volume, measured in vitro using the biosensor, was evaluated and compared with the stiffness of the prostate, seminal vesicles, testicles, and uterus. In 5 small anesthetized male rats, in vivo isovolumetric studies were performed and bladder stiffness was measured during the storage and contraction phase of the CMG. In 6 mature female rats, change in bladder stiffness during isovolumetric contractions was investigated following intraarterial (i.a.) administration of 0.1 and 1.0 mg/kg of oxybutynin. After the in vivo CMG was completed, an in vitro CMG was done measuring bladder stiffness. The results show that bladder stiffness, measured during the storage phase of the CMG, increased in accordance with the stretched length of bladder wall. During the in vivo CMG, bladder stiffness increased consequent to a spontaneous contraction from 10.0 ± 1.9 g/cm to 29.9 ± 3.0 g/cm (P < 0.005). Oxybutynin produced a significant decrease in bladder stiffness during the storage phase of the CMG, as measured using the biosensor, which was concomitant with an increase in bladder compliance derived from pressure/volume data. The incremental change in stiffness, ΔK, during isovolumetric contraction decreased due to i.a. oxybutynin in accordance with a decrease of maximum detrusor pressure. These results indicate that ΔK is related to the active change of viscoelastic properties of bladder smooth muscle. These findings imply that direct measurement of the stiffness of the bladder wall possesses the potential to be an objective assessment of bladder biomechanical properties and of their functional response to obstruction and pharmacological intervention. Neurourol. Urodynam. 16:567–581, 1997. © 1997 Wiley-Liss, Inc.     

The influence of filling rates and sympathectomy on bladder compliance in the chloralose-anaesthetised cat

The effect of total sympathectomy (hypogastric nerve and sympathetic chain section) on the relationship between bladder compliance and filling rate has never been studied over the full range of physiological filling rates. In a series of chloralose-anaesthetised cats, we examined the effect of total sympathectomy on bladder stiffness (the inverse of compliance) at filling rates from 1 to 50 hourly diuresis (HD) units. In control animals the slopes of regression lines fitted from 5 to 30 (n = 7) or 5 to 50 (n = 3) HD units were equal to or approached 0 (mean slope = .002 ± .0008 SE). After sympathectomy there was a statistically significant increase in stiffness at filling rates from 5 to 30 HD units (P < .005), and, although there was a trend for increased stiffness at higher filling rates, the increase in the slopes of the regression lines did not reach statistical significance (.05 < P < .1). The volume threshold for micturition at a filling rate of 5 HD units was significantly lowered after sympathectomy (P ≤ .0005). We conclude that the sympathetic nervous system makes a significant contribution to the control of bladder stiffness (and therefore compliance) within the range of physiological filling rates and that this effect may be more important at higher rates of filling. The sympathetic nervous system also has a role in determining the volume threshold for micturition at physiological filling rates.     

Lessons learned from the management of adults who have undergone augmentation for spina bifida and bladder exstrophy: Incidence and management of the non‐lethal complications of bladder augmentation

The present review provides clinical insights and makes recommendations regarding patient management garnered by the long‐term follow up of patients undergoing enteric bladder augmentation for the management of congenital anomalies. A prospectively maintained database on 385 patients that have experienced an enteric bladder augmentation, using either the ileum or colon, was reviewed. Evaluations included methods used to prevent bladder calculi formation and recurrence, the incidence and etiology of renal calculi development, the incidence and treatment of vitamin B₁₂ deficiency, and the complications and need for surgical revisions for continent catheterizable stomas. A significantly increased risk for continent catheterizable stomal complications occurred after Monti–Yang tube formation, 70% (21/30 patients), compared with appendicovesicostomy, 41% (27/66 patients), P = 0.008. Both procedures had significantly more complications than continent catheterizable stomas using tapered ileum with a reinforced ileal–cecal valve, 21% (13/63 patients), P < 0.0001 and P < 0.013, respectively. Approximately 50% of the patient population developed a body mass index ≥30 during adulthood. The onset of obesity resulted in significantly more complications developing in patients with a Monti–Yang tube (87%; 13/15 patients) or appendicovesicostomy (55%; 18/33 patients) compared with a tapered ileum with a reinforced ileal‐cecal valve (27%, 8/30 patients), P < 0.00015 and P < 0.025, respectively, with a median follow‐up interval of 16 years, range 10–25 years. Long‐term follow‐up evaluations on patients undergoing an enteric bladder augmentation are necessary to prevent the long‐term sequela of this procedure. The key to improving patient prognosis is the nutritional management of the patient as they mature, especially if a continent abdominal stoma is going to be carried out.     

Autoaugmentation peritoneocystoplasty in a sheep model

OBJECTIVE: To report our experience with autoaugmentation peritoneocystoplasty (AAPC) in a sheep model, and to compare the results with autoaugmentation gastrocystoplasty (AAGC) in a sheep model and in paediatric patients. MATERIALS AND METHODS: Ten 6-month-old male lambs underwent bladder augmentation by detrusorotomy. A flap of parietal peritoneum, dissected from the anterior abdominal wall, was used to cover the bladder mucosa. The sheep were evaluated by urodynamics 6 months after surgery. Bladder compliance (bladder volume/intravesical pressure) was calculated for the bladder capacity at leakage. The urodynamic results were compared with age-matched control sheep and with 12 sheep that had undergone AAGC; the results were assessed using the Mann-Whitney U-test. RESULTS: In two of the 10 sheep, bladder volumes after AAPC increased by > 100%, although for the group, the mean (range) bladder volume after augmentation, at 159 (42-261) mL, was not significantly different from that before surgery (mean 143 mL). Bladder volumes after AAPC were not significantly different from those in the control sheep (mean 205 mL) but were significantly less than in the AAGC group (mean 317 mL; P < 0.05). Bladder compliance at leak capacity in the AAPC group (mean 5.4 mL/cmH2O) was also not significantly different from the controls (mean 9.1 mL/cmH2O), but was lower than the in the AAGC animals (median 14.6 mL/cmH2O; P < 0.05). CONCLUSIONS: AAPC in a sheep model does not result in a reliable increase in bladder volume or compliance. The volume and compliance are inferior to those found in bladders augmented by AAGC.     

Effect of α1 adrenoceptor antagonist on the urodynamics of the upper and lower urinary tract of the male rat

In this investigation, we examined the impact of the α1 adrenoceptor (α1-ADR) antagonist prazosin on the urodynamic characteristics of upper urinary tract function and associated micturition characteristics of the adult male rat. The focus of the study was to evaluate the extent to which prazosin affects urine production and ureteral transport relative to its effect on micturition. Control micturition studies were first performed using 28 awake Sprague-Dawley rats that were placed in metabolic cages for characterization of the frequency and mean and total volume voided over a 4-hr period. Following the control studies, the effect of intraperitoneal prazosin, 30 μg/kg, was evaluated under identical conditions. Urodynamic studies were done to identify the bladder filling and voiding characteristics of anesthetized rats that were infused with saline at a rate of 0.22 ml/min. From the urodynamic studies the parameters of bladder pressure (P_ves) and volume (V) during filling, urethral opening (P_uo) measured at the moment of micturition, and maximum detrusor pressure during voiding (P_detmax) were evaluated. External sphincter electromyography was also monitored and recorded together with bladder pressure during voiding. Renal pelvic pressure was measured via a nephrostomy catheter and recordings were made simultaneously with bladder filling and voiding. The upper urinary tract was visualized using microscopic video imaging of the ureter, contrasted by perfusing the renal pelvis with indigo carmine. Characterization of upper tract transport was made in terms of renal pelvic pressure, ureteral peristaltic rate, and bolus length and velocity. The results show that in the awake rat, 30 μg/kg of prazosin decreased the urine production rate from 4.8 ± 0.074 to 1.6 ± 0.23 ml (P < 0.001) and micturition frequency by a similar proportion from 1.99 ± 0.44 to 0.53 ± 0.08/hr. In the lower urinary tract, prazosin did not change the baseline pressure of the bladder but produced significant dose-dependent decreases in P_detmax, P_uo, and frequency of micturition. In the upper urinary tract, ureteral and pelvic frequencies decreased, whereas the length of bolus increased significantly corresponding to increased doses of prazosin. These results suggest that, although prazosin facilitates micturition by reducing urethral opening pressure, it also reduces the rate of urine production and modulates the function of urine transport in the upper urinary tract. Neurourol. Urodynam. 17:213–229, 1998. © 1998 Wiley-Liss, Inc.     

Effects of doxycycline on voiding behaviour of rats with bladder outlet obstruction

OBJECTIVE

To examine the voiding behaviour changes in rats with bladder outlet obstruction (BOO) while inhibiting matrix metalloproteinase (MMP) activity with doxycycline, as increased MMP activity may be involved in obstruction‐induced bladder hypertrophy.

MATERIALS AND METHODS

Female Sprague‐Dawley were divided into eight groups (three rats in each group): normal control (NC) ± doxycycline, 3 weeks partial BOO (3WPBOO) ± doxycycline, 6 weeks PBOO ± doxycycline, and 3 weeks PBOO followed by 3 weeks de‐obstruction (3WOD) ± doxycycline. All rats received the same food and water and were on the same 12 h dark/light cycle housed in metabolic cages. Treatment groups were given doxycycline 15 mg/kg/day subcutaneously twice daily. The voiding variables measured were average voided volume (AV V) and voiding frequency (VF) in 24 h. After completion of the voiding behaviour studies, the rats were killed and their bladders were excised and weighed.

RESULTS

The AV Vs were significantly increased (P < 0.05) in all study groups compared with the NC group except for the 3WPBOO‐doxycycline and 3WOD‐doxycycline groups. The VF was significantly increased (P < 0.05) only in the 3WOD‐doxycycline group. The bladder weights were significantly increased after PBOO in all the study groups (P < 0.05), except for the 3WOD group.

CONCLUSION

These data show that MMP inhibition may affect voiding behaviour during the response to BOO or its relief. This is the first clinical demonstration that interfering with a principal target of bladder muscle wall remodelling may have a direct effect on bladder function.     

Involvement of angiotensin II type 1 receptor on pathological remodeling and dysfunction in obstructed bladder

Objectives: To determine whether long‐term administration of an angiotensin II type 1 receptor antagonist improves morphology and function in obstructed bladders. Methods: Male Sprague–Dawley rats underwent surgery to produce bladder outlet obstruction (bladder outlet obstruction group; n = 32) or sham surgery (sham group; n = 16). A total of 2 weeks later, 16 bladder outlet obstruction‐rats were given the AT1 antagonist, candesartan, subcutaneously (candesartan group) using an osmotic pump for 4 weeks; the remaining bladder outlet obstruction‐rats received vehicle (bladder outlet obstruction group). A total of 6 weeks after surgery, we compared continuous cystometry, bladder weight, strip contraction, histology and messenger ribonucleic acid expression of growth factors, nicotinamide adenine dinucleotide phosphate oxidase 1 and renin–angiotensin system components among the three groups. Results: Bladder weights markedly increased with bladder outlet obstruction (578 ± 159 mg), and candesartan (344 ± 111 mg) suppressed this increase. Micturition pressure, which was significantly higher with bladder outlet obstruction, was unaffected by candesartan. The shortened micturition interval and decreased micturition volume with bladder outlet obstruction were significantly prolonged and increased by candesartan. Candesartan also significantly decreased residual urine. Histologically, the collagen fiber‐to‐muscle ratio was significantly increased with bladder outlet obstruction (0.85 ± 0.25) compared with the sham group (0.53 ± 0.18); this increase was suppressed by candesartan (0.49 ± 0.21). The messenger ribonucleic acid expression of heparin‐binding epidermal growth factor‐like growth factor, transforming growth factor‐β1 and nicotinamide adenine dinucleotide phosphate oxidase 1 significantly increased with bladder outlet obstruction, but it was significantly reduced by candesartan. Compared with the bladder outlet obstruction group, candesartan increased the maximal contraction of bladder strips for all stimuli except for angiotensin II. Conclusion: These findings suggest that bladder angiotensin II type 1 receptors contribute to the pathophysiology of remodeling and dysfunction in obstructed bladder.