Evaluation Methods of Detrusor Sphincter Dyssynergia in Spinal Cord Injury Patients: A Literature Review

Round 1

Reviewer 1 Report

The aim of this manuscript is to evaluate the instrumental evaluation methods of detrusor-sphincter dyssynergia in spinal cord injury patients. The authors concluded that urodynamic methods add accuracy in diagnosing DSD in SCI individuals.

I believe that the study has sufficient merit to be considered for publication on Uro, although major revisions are required.

MAJOR COMMENTS

• In line 64 there is a mistake: ureteral instead of urethral.
• Related to line 76, what is the risk of neoplasia in patients with DSD?
• In line 131 shows the exact number of patients between men and women ( 56 men and 20 women).
• In paragraph 3.1.1.5., what is the rationale for the use of ultrasound technology in the study of DSD?
• It will be for the benefit of the reader if the author add figures about the mechanism behind the DSD and also a flow-chart about the included or excluded studies.
• In the managment of these patients, do you think that cistoscopy is necessary to rule out urethral strictures which might affect these studies ?

Author Response

MAJOR COMMENTS

• In line 64 there is a mistake: ureteral instead of urethral.

Thank you for this correction

• Related to line 76, what is the risk of neoplasia in patients with DSD?

There is literature with long term follow-up of SCI patients and urologic complications including neoplasms as bladder cancer. Nevertheless, as far as I know there is no publication  that studied the neoplasia risks specifically in DSD patients.

Interestingly in Ismail  et al. Systematic review of bladder cancer in sci patients with neurogenic bladde (includind DSD and other forms of neurogenic bladder):

0,3 % prevalence bladder cancer in neurogenic bladder SCI patients

Younger age at diagnosis when compared with general population

More aggressive forms of bladder cancer

Presence of indwelling or suprapubic catheters in 44.5% of bladder cancer SCI patients…

• In line 131 shows the exact number of patients between men and women ( 56 men and 20 women).

Thank you for this correction

• In paragraph 3.1.1.5., what is the rationale for the use of ultrasound technology in the study of DSD?

Any image modality that allows to observe directly the dynamic behaviour of the bladder neck and EUS during urodynamics adds accuracy and facilitates interpretation. This is the interest of VCUG while performing urodynamics. US has advantages when compared to VCUG (no radiation for patient and examiner, allows to observe soft tissue lake bladder wall, prostate … not seen with VCUG)

In the 3 mentioned papers (Perkash, Shapeero and Shabshig) a transrectal US probe was used. The figures presented in their papers of the 2D US images of the bladder neck, proximal urethra and pelvic floor/external Urethral sphincter are simply outstanding.  They seemed to have easily visualized in real time the anatomy and the behavior of the bladder neck and EUS.

• It will be for the benefit of the reader if the author add figures about the mechanism behind the DSD and also a flow-chart about the included or excluded studies.

Following your recommendation, I will add figures of urodynamic studies graphs of the types of DSD.

As for the flowchart we can do one.

• In the management of these patients, do you think that cystoscopy is necessary to rule out urethral strictures which might affect these studies ?

Cystoscopy is valuable to rule out structural obstruction, special when there is high suspicion of that conditions but I don't think it should be done in a regular basis.

In urodynamics one should expect a variation in EMG activity and/or EUS pressure in DSD which is a manifestation of a contraction of the EUS and not of a structural alteration.

Anyway in profilometry phase of urodynamics when a fixed high pressure is found, a structural obstruction should be ruled out (Transrectal US, cystoscopy as first intention diagnostic exams)

Since Cystoscopy can trigger autonomic dysreflexia episodes in above T6 SCI patients, it should be considered carefully and performed in centers with experience in dealing with these  patients

Reviewer 2 Report

The authors conducted a literature review for detrusor sphincter dyssynergia (DSD) in spinal cord injury (SCI) patients. I have the following comments and suggestions.

1. Introduction: It is better to provide two UDS figures to compare the differences of intermittent (type 1) and continuous (type 2) DSD. It will be the best to provide two video-urodynamic study figures.
2. The approximate prevalence of type 1 and type 2 DSD in patients with incomplete neurologic lesions and complete lesions should be shown.
3. The definition might be clarified. “ DSD may also occur in non-neurological pathologies”. Failure of the external urethral sphincter-pelvic floor complex to relax appropriately during voiding in patients with neurogenic pathologies is DSD? Failure of the external urethral sphincter-pelvic floor complex to relax appropriately during voiding in patients without neurogenic pathologies is dysfunctional voiding?
4. The current treatment of DSD is needed. Maybe in section 3.2.5.
5. Any studies comparing the differences of suprapubic catheter or transurethral catheter for diagnosing DSD?
6. Introduction: A combination of recordings of VCUG and EUS EMG, with or without EUS pressure measurement is the most accurate method available to evaluate DSD. Case # 1: VCUG (+), EUS EMG (-), EUS pressure measurement (-)

Case # 2: VCUG (-), EUS EMG (+), EUS pressure measurement (-)

Case # 3: VCUG (-), EUS EMG (-), EUS pressure measurement (+)

Could case #1~3 be diagnosed as DSD if only criteria was achieved?

Author Response

1. Introduction: It is better to provide two UDS figures to compare the differences of intermittent (type 1) and continuous (type 2) DSD. It will be the best to provide two video-urodynamic study figures.------------------

Thank you for your pertinent remarks

We will add  figures of urodynamic graphics showing DSD from our clincial database

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1. The approximate prevalence of type 1 and type 2 DSD in patients with incomplete neurologic lesions and complete lesions should be shown.

We did not find any study mentioning the prevalence of the 2 types.

We could not find neither a clear anatomiy and pathophysiologic explanation for the different types presentation

We also searched for studies explaining  the clinical rational of dividing the DSD in different types.

We did not find any study explaining the clinical interest in dividing DSD in 2 or more types.

In our clinical practice, type 1 would be candidate for reflex voiding (facilitated by Botulinum Neurotoxine  EUS injection) whether possible but for type 2, micturition by reflex is almost impossible and Intermittent bladder catheterization when possible, could be associated with BoNTA injections.

But we take into consideration a multitude of other clinical features when deciding for the best bladder drainage strategy

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1. The definition might be clarified. “ DSD may also occur in non-neurological pathologies”. Failure of the external urethral sphincter-pelvic floor complex to relax appropriately during voiding in patients with neurogenic pathologies is DSD? Failure of the external urethral sphincter-pelvic floor complex to relax appropriately during voiding in patients without neurogenic pathologies is dysfunctional voiding?

Well, this is exactly what we found while doing this review. In one hand there is an ongoing  effort of reaching expert consensus in defining DSD like what is done by International Continent Society ICS that states that DSD occurs only in neurologic conditions, on the other hand we found recent studies describing DSD in conditions that don't fit the ICS definition. This claims for further efforts in clarifying the DSD  entities so there is a common language and concepts when discussing this subject.

From our standpoint we cannot clarify the definition, but we aim to highlight the lack of unanimity and encourage the effort for a clarification that should be done by scientific societies like the ICS

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1. The current treatment of DSD is needed. Maybe in section 3.2.5.

The treatment is not in the scope of this review, however we  agree that for clinicians that aren't familiar with this entity, at least it should be briefly mentioned. We will do it

1. Any studies comparing the differences of suprapubic catheter or transurethral catheter for diagnosing DSD?

I don't understand your remark here.  We don'tn know any configurations of urodynamics using a suprapubic catheter/probe to measure intrevesical pressure for instance

Anyhow, A presence of a suprapubic catheter for urine drainage can be considered an irritative stimulus that might aggravate the DSD presentation. In our practice, a patient has a suprapubic catheter because we could not find a better alternative for bladder drainage.,In theses cases, we perform the normal urodynamics exam using a transurethral probe/catheter, with the suprapuic cathter in place this will allows us to know the bladder dysfunction in real life circumstances, and therefore to define the therapeutic plan accordingly

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1. Introduction: A combination of recordings of VCUG and EUS EMG, with or without EUS pressure measurement is the most accurate method available to evaluate DSD. Case # 1: VCUG (+), EUS EMG (-), EUS pressure measurement (-)

Case # 2: VCUG (-), EUS EMG (+), EUS pressure measurement (-)

Case # 3: VCUG (-), EUS EMG (-), EUS pressure measurement (+)

Could case #1~3 be diagnosed as DSD if only criteria was achieved?

Well, yes, when evaluating a SCI with suprasacral lesion, the likelihood of having DSD is high, so if only one of those parameter is suggestive of DSD one can assume the diagnosis. 

Nevertheless, while using 2 or the 3 methods (EUS EMG; VCUG; EUS Pressure) combined, all of them should be coherent with the DSD diagnosis at the same time. For instance if the EMG activity in the EUS is important and at the same time the VCUG show an opened EUS and there is micturation observed, one should check the EMG signal for noise or artefacts.

Reviewer 3 Report

327 Concern about –

Abst - Besides the instrumental diagnosis, health professionals should consider additional clinical features 24 when evaluating and managing DSD in SCI patients, to design a customized plan to achieve the 25 best compromise between quality of life and urinary system protection.

329 - - On the other hand, in SCI with DSD, urodynamics severity parallels with progression to deterioration of the upper renal tract and are the basis of diagnosis and the management plan in these patient.

CONCERN - In this and related section, the current method of patient management is not identified as an important factor about - what and when DSD and urodynamic methods should be used.

Further,

1. DSD diagnosis and cysto with EMG is less frequently needed in a patient on IC, anticholinergic medicine and without incontinence. These patients are well managed and little risk for the kidney and less in need of urodynamics.
2. Patients on Foley Catheters – what is your opinion about when they need Urodynamics for DSD
3. Reflex voiding patients, these are the patients with real risks of DSD causing high bladder pressures and kidney problems. It is primarily in these patients that DSD assessment makes a difference. Reflex voiding relies on limited DSD and limited urethral sphincter contraction during bladder contractions to have voiding with limited residual volume. They should be monitored for DSD assessment more often.

CONCERN – Urodynamics and cystourethrography require time and expense. Discussion what and when warranted for assessment of DSD.  Reflex voiding is most mandatory.

CONCERN – Solar paper; with 99 reflex voiding patients receiving BT injections in the sphincter and reflex voiding, this has changed the field; DSD is monitored very well in this patient group.  Spinal Cord (2016) 54, 452–456.  Please include this paper and discuss how it is modifying DSD management and urodynamic monitoring.

119  n 63%, and rise in urethral pressure    change to     a rise

Line 218     These findings should arise ques-     change to raise

312   6) and his commonly associated with DSD           to has

316   , a debit of 2      to a rate of

310 – a discussion of bladder contractions causing autonomic dysreflexia is needed – it is considered a major factor

SUGGESTION – mention that the anus can be palpated during bladder contractions and cystometry to determine if DSD is present, the contractions can be determined from slight to moderate to strong.

Should also mention that EMG is usually from the anal sphincter and the anal and urethral sphincters contract simultaneously after SCI and MS.

Author Response

We appreciate your valuable suggestions and remarks to our review.

On detail: 

Abst - Besides the instrumental diagnosis, health professionals should consider additional clinical features 24 when evaluating and managing DSD in SCI patients, to design a customized plan to achieve the 25 best compromise between quality of life and urinary system protection.

329 - - On the other hand, in SCI with DSD, urodynamics severity parallels with progression to deterioration of the upper renal tract and are the basis of diagnosis and the management plan in these patient.

CONCERN - In this and related section, the current method of patient management is not identified as an important factor about - what and when DSD and urodynamic methods should be used.

Thank for your valuable remarks.

We will add to the article that the current method of DSD management including bladder drainage strategy has to be integrated in the management plan

We keep in mind that In our review the management and treatment of DSD is not the main focus, we aim to review the different methods of evaluating DSD

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1. DSD diagnosis and cysto with EMG is less frequently needed in a patient on IC, anticholinergic medicine and without incontinence. These patients are well managed and little risk for the kidney and less in need of urodynamics.

Certainly burden, access and availability of urodynamics expertise plays a role in clinical practice when deciding the rythm of follow-up. In our review we advice to have a minimun routine follow-up framework which has to include urodynamics, and adapt it according to other clinical features for every patient.

Some examples:

If a pateint who had undergone sphincterectomy starts having more frequent AD episodes, that should prompt for a check up on the bladder-sphincter dysfonction as soon as possible. Conversely, a patient that is stable, able to do IC, tolerate anti-Ach medicine can wait longer time  (more than 1 year) for routine evaluation

Anyhow, the aim of our review was not to focus on management DSD, which is discussed elsewhere in the literarature, but to focus on the different methods of evaluating DSD

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Patients on Foley Catheters – what is your opinion about when they need Urodynamics for DSD

It depends again in the clinical scenario, respecting the principle of clinical pertinence and avoiding  futile exams

2 examples

A patient admitted in Rehab ward that comes form the acute care with a recent spinal cord injury and a Foley catheter is frequently in the spinal shock phase. In our clinical practice, we ablate the foley catheter we start a strict bladder diary (every 4 h) with bladder ultrasound - bladderscan, and bladder drainage is done by the nurses (in-out bladder catherization) when needed. As the patient emerges form spinal shock an urodynamics is scheduled, allowing sufficient time after the Foley ablation

Another exemple, A MS patient for which the strategy for bladder drainage is to have a foley catheter ,(idwelling) who is stable, and has a pre-establish diagnosis of DSD. Urodynamics might be futile in this setting.

Anyhow, we do our best to avoid the Foley cathrters as a bladder drainage strategy  in chronic patients since it is associated with a high rate of complications

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1. Reflex voiding patients, these are the patients with real risks of DSD causing high bladder pressures and kidney problems. It is primarily in these patients that DSD assessment makes a difference. Reflex voiding relies on limited DSD and limited urethral sphincter contraction during bladder contractions to have voiding with limited residual volume. They should be monitored for DSD assessment more often.

CONCERN – Urodynamics and cystourethrography require time and expense. Discussion what and when warranted for assessment of DSD.  Reflex voiding is most mandatory.

Part of the answer for this remark was done previously.

And we agree that in patients for whom the plan for bladder drainange is reflex voiding, the clinician should be certain that this plan represents a lower risk for the urinary system, then only urodynamics can give a reliable indication of that risk and therefore should be performed frequently in these patients. We can add it briefly but since the aim of the review is not DSD management and for the benefit of the reader we don't think we should insist too much in these points

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CONCERN – Solar paper; with 99 reflex voiding patients receiving BT injections in the sphincter and reflex voiding, this has changed the field; DSD is monitored very well in this patient group.  Spinal Cord (2016) 54, 452–456.  Please include this paper and discuss how it is modifying DSD management and urodynamic monitoring.

As discussed above we will follow your recommendation, and  add this paper as the reference for the disscussion

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119  n 63%, and rise in urethral pressure    change to     a rise

Line 218     These findings should arise ques-     change to raise

312   6) and his commonly associated with DSD           to has

316   , a debit of 2      to a rate of

 We appreciate your careful review and remarks

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310 – a discussion of bladder contractions causing autonomic dysreflexia is needed – it is considered a major factor

SUGGESTION – mention that the anus can be palpated during bladder contractions and cystometry to determine if DSD is present, the contractions can be determined from slight to moderate to strong.

Should also mention that EMG is usually from the anal sphincter and the anal and urethral sphincters contract simultaneously after SCI and MS.

 -

Thanks for this insight.

In our review we prefer to keep focused in DSD evaluation, we mention AD as it has important clinical implications in this popilation of SCI patients but we rather not explore further the AD topic.

We prefer not to encourage examiners to palpate the anus in order not to interfere and/or cause artifacts with the abdominal pressure probe that is usualy intrarectal.

Round 2

Reviewer 1 Report

I believe that the study has sufficient merit to be considered for publication on Uro 

Author Response

Thank you for your suggestion of improvement,

the flow chart according to PRISMA template was included in the manuscrit resubmission