Intravesical Heparin and Peripheral Neuromodulation on Interstitial Cystitis

Current role of neuromodulation in bladder pain syndrome/interstitial cystitis

Neuromodulation is recommended by major international guidelines as a fourth-line treatment in bladder pain syndrome/interstitial cystitis (BPS/IC) patients after failure of behavioural, oral and intravesical pharmacological treatments, including hydrodistension. A non-systematic review of studies identified by electronic search of MEDLINE was performed with no time limitation. A narrative synthesis of the existing evidence regarding the results of sacral, tibial and pudendal nerve stimulation in the management of BPS/IC was developed. Neuromodulation in pelvic chronic pain disorders, including BPS/IC, is a useful tool for refractory patients to conventional treatments. Sacral neuromodulation may be effective in patients with BPS without Hunner's lesions, and the effect seems to be maintained in the mid- and long-term. Posterior tibial nerve stimulation can be offered to patients with BPS/IC in the context of a multidisciplinary approach. When pudendal neuralgia is suspected, selective pudendal nerve stimulation has a high response rate. The aetiology of the pain can influence the outcomes in the mid- and long-term of the different neuromodulation approaches, thus careful diagnosis is recommended.

Neuromodulation for Pelvic and Urogenital Pain

Chronic pain affecting the pelvic and urogenital area is a major clinical problem with heterogeneous etiology, affecting both male and female patients and severely compromising quality of life. In cases where pharmacotherapy is ineffective, neuromodulation is proving to be a potential avenue to enhance analgesic outcomes. However, clinicians who frequently see patients with pelvic pain are not traditionally trained in a range of neuromodulation techniques. The aim of this overview is to describe major types of pelvic and urogenital pain syndromes and the neuromodulation approaches that have been trialed, including peripheral nerve stimulation, dorsal root ganglion stimulation, spinal cord stimulation, and brain stimulation techniques. Our conclusion is that neuromodulation, particularly of the peripheral nerves, may provide benefits for patients with pelvic pain. However, larger prospective randomized studies with carefully selected patient groups are required to establish efficacy and determine which patients are likely to achieve the best outcomes.

Intravesical treatment of bladder pain syndrome/interstitial cystitis: from the conventional regimens to the novel botulinum toxin injections

INTRODUCTION

Bladder pain syndrome (BPS) includes interstitial cystitis (IC) and is often used as a synonym of it (i.e., BPS/IC). It is associated with lower urinary tract symptoms as well as with negative cognitive, behavioral, sexual and/or emotional consequences. Unfortunately, none of the numerous existing oral and intravesical treatments have been effective for all of the BPS subtypes and therefore relevant research is ongoing.

AREAS COVERED

In this review, the authors analyze the existing literature for the intravesical treatment of BPS/IC with focus on the novel administration of botulinum toxin (BTX). Several intravesical drugs have been studied in the past, including lidocaine, heparin, pentosan polysulfate sodium, dimethyl sulfoxide, chondroitin sulfate, hyaluronic acid as well as investigational drugs such as GM-0111. Recently, intravesical submucosal injections of BTX have been studied in patients with BPS/IC.

EXPERT OPINION

Most of the recent studies use BTX-A with no serious adverse effects and with satisfactory results in patients who do not respond to oral or standard intravesical therapy. Nevertheless, there is no consensus regarding the best dosage scheme of BTX, the injection sites and the treatment intervals. BTX intravesical administration in patients with BPS/IC is a safe and efficient treatment option; yet the level of evidence of the initial studies is not high. There is still the need for large randomized controlled studies so that a consensus can be reached for the ideal BTX dosage, injection sites and intervals between treatments.

Percutaneous Tibial Nerve Stimulation (PTNS) efficacy in the treatment of lower urinary tract dysfunctions: a systematic review

Background

Percutaneous Tibial Nerve Stimulation (PTNS) has been proposed for the treatment of overactive bladder syndrome (OAB), non-obstructive urinary retention (NOUR), neurogenic bladder, paediatric voiding dysfunction and chronic pelvic pain/painful bladder syndrome (CPP/PBS). Despite a number of publications produced in the last ten years, the role of PTNS in urinary tract dysfunctions remains unclear. A systematic review of the papers on PTNS has been performed with the aim to better clarify potentialities and limits of this technique in the treatment of OAB syndrome and in other above mentioned urological conditions.

Methods

A literature search using MEDLINE and ISI web was performed. Search terms used were “tibial nerve” and each of the already mentioned conditions, with no time limits. An evaluation of level of evidence for each paper was performed.

Results

PTNS was found to be effective in 37-100% of patients with OAB, in 41-100% of patients with NOUR and in up to 100% of patients with CPP/PBS, children with OAB/dysfunctional voiding and patients with neurogenic pathologies. No major complications have been reported.

Randomized controlled trials are available only for OAB (4 studies) and CPP/PBS (2 studies). Level 1 evidence of PTNS efficacy for OAB is available. Promising results, to be confirmed by randomized controlled studies, have been obtained in the remaining indications considered.

Conclusions

PTNS is an effective and safe option to treat OAB patients. Further studies are needed to assess the role of PTNS in the remaining indications and to evaluate the long term durability of the treatment. Further research is needed to address several unanswered questions about PTNS.

A murine model of inflammatory bladder disease: cathelicidin peptide induced bladder inflammation and treatment with sulfated polysaccharides

PURPOSE

Studies show that LL-37 is a naturally occurring urinary defensin peptide that is up-regulated during urinary tract infections. Although normal urinary LL-37 levels are antimicrobial, we propose that increased LL-37 may trigger bladder inflammation. We further suggest that anti-inflammatory sulfated polysaccharides known as semi-synthetic glycosaminoglycan ether compounds can treat/prevent LL-37 mediated bladder inflammation.

MATERIALS AND METHODS

C57BL/6 mice were catheterized/instilled with LL-37 (320 μM, 150 μl) for 45 minutes. Animals were sacrificed at 12 and 24 hours, and tissues were examined using hematoxylin and eosin. Separate experiments were performed for myeloperoxidase to quantify inflammation. GM-1111 semi-synthetic glycosaminoglycan ether treatments involved instillation of 10 mg/ml for 45 minutes directly before or after LL-37. Tissues were harvested at 24 hours. To compare semi-synthetic glycosaminoglycan ether efficacy, experiments were performed using 10 mg/ml heparin. Finally, tissue localization of semi-synthetic glycosaminoglycan ether was examined using a fluorescent GM-1111-Alexa Fluor® 633 conjugate.

RESULTS

Profound bladder inflammation developed after LL-37. Greater tissue inflammation occurred after 24 hours compared to that at 12 hours. Myeloperoxidase assays revealed a 21 and 61-fold increase at 12 and 24 hours, respectively. Semi-synthetic glycosaminoglycan ether treatment after LL-37 showed mild attenuation of inflammation with myeloperoxidase 2.5-fold below that of untreated bladders. Semi-synthetic glycosaminoglycan ether treatment before LL-37 demonstrated almost complete attenuation of inflammation. Myeloperoxidase results mirrored those in controls. In heparin treated bladders minimal attenuation of inflammation occurred. Finally, instillation of GM-1111-Alexa Fluor 633 revealed urothelial coating, significant tissue penetration and binding to endovasculature.

CONCLUSIONS

We developed what is to our knowledge a new model of inflammatory bladder disease by challenge with the naturally occurring urinary peptide LL-37. We also noted that a new class of anti-inflammatory sulfated polysaccharides prevents and mitigates bladder inflammation.

[Specific treatments for painful bladder syndrome]

INTRODUCTION

Painful bladder syndrome is defined as chronic pelvic pain present for more than 6 months, causing discomfort perceived as being related to the bladder and accompanied by a persistent and strong urge to urinate or urinary frequency. The purpose of this article is to review the treatment of painful bladder syndrome.

MATERIAL AND METHODS

A comprehensive review of the literature was performed by searching PUBMED for articles on specific treatments for painful bladder syndrome.

RESULTS

Many treatments have been proposed for the management of painful bladder syndrome: local intravesical treatments (glucosaminoglycan [pentosan polysulfate], dimethylsulfoxide [DMSO], heparin, bacillus Calmette-Guérin [BCG], anticholinergic agents [oxybutynin, etc.] or oral treatments [glucosaminoglycan (pentosan polysulfate), antihistamines, antidepressants, immunosuppressives, etc.]) with an action on the pathophysiology of this syndrome. The efficacy of these various treatments has been limited, with trials based on small numbers of patients and not always conducted according to a randomized, prospective design. Other salvage treatments (neuromodulation, botulinum toxin, surgery, etc.) have also been reported with limited efficacy, but allowing salvage of treatment failures.

CONCLUSION

The therapeutic management of painful bladder syndrome is complex. The large number of proposed treatment modalities present a limited efficacy with discordant results from one study to another making comparisons and analyses difficult.

Current opinion on the working mechanisms of neuromodulation in the treatment of lower urinary tract dysfunction

PURPOSE OF REVIEW

Neuromodulation is a successful treatment for patients with refractory lower urinary tract dysfunction. In the recent years, more applications of various types and ways have been developed and put into clinical practice. It is important, therefore, for urologists to know the existing theories on the working mechanisms that explain the effect. Although much research has been devoted to this subject for the past 35 years, the working mechanism is still unknown. This review presents an overview of the different theories and research into the physiological background of neuromodulation during the past 3 decades with emphasis on recent developments.

RECENT FINDINGS

Specific receptors in the spinal cord have been identified, which are involved in the working mechanism of neuromodulation. The maximal effect of neuromodulation is not directly reached, indicating that neuromodulation induces learning changes (i.e. neural plasticity). The carry-over effect could be caused by negative modulation of excitatory synapses in the central micturition reflex pathway.

SUMMARY

Neuromodulation in the treatment of stress incontinence probably induces physiological changes in the sphincter muscles and pelvic floor. In the treatment of overactive bladder syndrome, nonobstructive voiding dysfunction and chronic pelvic pain, the mechanism of action seems to be more complicated. Most likely, it is a combination of the different suggested modes of action, involving the neuroaxis at different levels.

Recent developments of intravesical therapy of painful bladder syndrome/interstitial cystitis: a review

PURPOSE OF REVIEW

Painful bladder syndrome/interstitial cystitis is a chronic sterile inflammatory disease of the bladder of unknown cause. It is characterized by bladder pain, urinary frequency, urgency, and nocturia. Although there are plenty of theories, the cause of the condition remains obscure. An abundance of treatments has been suggested, but very few have been subjected to proper controlled trials. This review focuses on the recently published literature on intravesical therapy strategies in painful bladder syndrome/interstitial cystitis.

RECENT FINDINGS

Bladder irrigation with different agents has been used during years in an attempt to treat painful bladder syndrome/interstitial cystitis. The background for this is the existing theories about urothelial dysfunction. The 'traditional' agent for glycosaminoglycan substitution is hyaluronic acid. Often used are heparin and dimethyl sulfoxide, the actions of which are not quite clear but supposedly on an anti-inflammatory basis. Other agents for intravesical treatment are Bacillus Calmette-Guerin vaccine and botulinum toxin, and some recent studies have pointed to resiniferatoxin and RDP58.

SUMMARY

Painful bladder syndrome/interstitial cystitis persists as a challenging syndrome in urology. Intravesical instillation therapy has basically not changed during the last few years, although some studies have disconfirmed some regimens. Intensive research may hopefully result in more effective treatments in the future.