Int J Colorect Dis (1991) 6:202-207

Col6 'eeml Disease 9 Springer-Verlag 1991

Biofeedback defaecation training for anismus B. Lesthr, E Penninckx and R. Kerremans

Department of Abdominal Surgery, University Clinic Gasthuisberg, KatholiekeUniversiteit Leuven, Leuven, Belgium Accepted: 3 June 1991

Abstract. Anismus, paradoxical external sphincter func-

tion, spastic pelvic floor syndrome, rectoanal dysnergia, abdomino-levator incoordination for abdominopelvic asychronism, are all due to paradoxical contraction of the striated sphincter apparatus during voiding and is characterised by prolonged and excessive straining at stool. Biofeedback is the treatment of choice and has to be introduced at an early stage. We present the results of an ambulatory approach based on the integration of simulated balloon defaecation with small (50 ml) as well as constant rectal sensation volume, defaecometry and anal manometry. The pathophysiology visualised by the patient's own anorectal pressure recordings on the screen of a personal computer is explained and corrected. Sixteen patients were treated and followed for at least 1 year. Manometric data were normal except for an increased minimum residual pressure and rectal compliance. Nine patients could not evacuate a 50 ml bolus initially. Simulated defaecation became possible in seven out of these nine patients when the bolus was increased up to the individual constant rectal sensation volume. Two patients could not evacuate this volume either, while defaecation was made much less laborious in the other seven patients. Paradoxical contraction was immediately corrected in 7/16 cases. Also, as an immediate, objective benefit of a single training session, improved defaecation of a 50 ml bolus was observed in 11 patients. This effect was preserved after 6 weeks in nine cases; symptomatic recurrence did not occur in these patients during followup. This method of defaecation training has many advantages as compared with sphincter training using EMG electrodes eventually performed in the absence of a desire to defaecate or in lying position. It does not work, however, in all patients, especially in those with a "blind" rectum. Defaecometry is a valuable tool for the objective assessment of therapeutic effectiveness in patients with anismus. R6sum6. L'anisme, contraction paradoxale du sphincter

externe, syndrome du plancher pelvien spastique, dyssy-

nergie ano-rectale, incoordination abdomino-sphinct6rienne ou asynchronisme abdomino-pelvien, est du fi une contraction pradoxale de l'appareil sphinct6rien stri6 durant la d6f6cation et est caract6ris6 par des efforts prolong6s et excessifs lors des selles. Le Biofeedback est le traitement de choi et doit 6tre commenc6 fi un stade pr6coce. Nous pr6sentons les r6sultats d'un traitement ambulatoire bas6 sur l'int6gration d'une d6f~cation simul6e par un ballon avec un petit (50 ml) et aussi avec un volume de sensation rectale constante, une d6f6com6trie et une manom6trie anale. La physiopathologie des trac6s de la pression ano-rectale propre du patient, visualis6e sur un 6cran d'un ordinateur personnel est expliqu6e et corrig6e. Les constatations manom6triques 6taient normales l'exception d'une augmentation de la pression r6siduelle minimale et de la compliance rectale. 9 malades ne pouvaient ~vacuer initialement un bolus de 50 ml. La d6f6cation simul6e est evenue possible chez 7 d'entre eux lorsque le bolus a 6t6 augment6 jusqu'au volume individuel de sensation rectale constante. 2 patients n'ont pas pu 6vacuer ce volume tandis que la d6f6cation devenait beaucoup moins laborieuse chez les 7 autres patients. La contraction paradoxale a 6t6 corrig~e imm6diatement chez 7 des 16 malades. Ainsi, comme un b6n6fice imm6diat objectif apr6s une simple s6ance de biofeedback, une amblioration de la d6f6cation d'un bolus de 50 ml a bt6 observ6e chez 11 patients. Ce r6sultat persistait apr6s six semaines dans 9 cas. Une r~currence symptomatique n'est pas apparue chez ces malades durant le suivi. Cette m6thode d'6ducation d&6catoire a beaucoup d'avantages compar6e avec une r66ducation sphinct6rienne utilisant des 61ectrodes d'61ectromyographie 6ventuellement rbalishe en l'absence de tout d6sir de d6f6cation ou en position couch6e. Elle n'agit cependant pas chez tousles patients, sp6cialement ches ceux qui ont un rectum "aveugle". La d6f6com6trie est un outil de valeur pour le contr61e objectif de l'efficacit~ th6rapeutique chez les patients ayant un anisme.

203

Introduction C o n s t i p a t i o n due to pelvic outlet obstruction concerns patients with laborious or impossible s p o n t a n e o u s defaecation [1, 2]. D u r i n g the n o r m a l straining act the striated sphincter a p p a r a t u s relaxes, the rectoanal angle becomes m o r e obtuse and the increased i n t r a - a b d o m i n a l and rectal pressure expel the rectal content [3-5]. E v a c u a t i o n becomes difficult if the sphincter apparatus, especially the puborectalis muscle, does n o t relax or contracts during voiding [2, 6 - 9 ] . This type o f pelvic outlet obstruction is characterised b y p r o l o n g e d and excessive straining at stool. It has been called paradoxical external sphincter function [10], spastic pelvic floor s y n d r o m e [8], anismus [9], rectoanal dysynergia [11], a b d o m i n o - l e v a t o r incoordination [12], and a b d o m i n o p e l v i c a s y n c h r o n i s m [13]. It contributes to the development o f solitary rectal ulcer, rectal prolapse, rectocele and h a e m o r r h o i d s [14-16]. Perineal descent during excessive straining also can result in incontinence, mainly due to pudendal nerve elongation and n e u r o p a t h y [17 - 19]. F u n c t i o n a l anorectal outlet obstruction also increases the segmental transit time o f the left and right colon, simulating the complex motility disorders o f slow colon transit constipation [20]. This supports the view that disturbed defaecation always has to be cured first in every constipated case [21]. It is obvious that patients with anismus should be detected and treated at an early stage. T h e diagnosis o f anismus m a y be based on evacuation or balloon p r o c t o g r a p h y [2, 2 2 24], on e l e c t r o m y o g r a p h y [8, 9, 23, 25, 26] or on anal m a n o m e t r y during straining [10, 25, 2 7 - 2 9 ] , on balloon evacuation tests [9] or on defaecometry [30]. It remains controversial which m e t h o d is superior. Therefore, it is wise to s u p p o r t the diagnosis by the results o f two or m o r e o f these investigations p e r f o r m e d on different occasions. Laxatives, high fibre diet and bowel training in the sense o f scheduling o f toileting usually fail because they do n o t treat the cause [31, 32]. Puborectalis division [ 3 3 35] or internal s p h i n c t e r o t o m y [36, 37] had no success for the same reason. L a r g e enemas are needed or the stool has to be evacuated digitally. Since anismus is caused by the a b n o r m a l function o f an apparently n o r m a l striated musculature, it has been recognised that it is possible for such patients to learn h o w to relax their pelvic floor and anal muscles during defaecation again [10, 25, 28, 38]. O p e r a n t conditioning using e l e c t r o m y o g r a p h i c [13, 26, 28, 38] or m a n o m e t r i c devices [10, 28, 29] as the biofeedback link to sphincter control p r o v e d to be a valuable tool. Kinesitherapeutic relaxation exercises and psychological classes m a y be i m p o r t a n t adjuvants. A conventional therapeutic regimen with high fibre diet and eventually laxatives is also an i m p o r t a n t c o m p l e m e n t in the treatment o f these patients since m a n y o f them m a y have small and hard stools. Indeed, m o r e effort is required to expel stools if they are small and h a r d than if they are large and soft [391. We have therefore integrated the defaecometry technique [30] in biofeedback training o f patients with anismus using rectal balloons located just above the anal canal and filled with 50 ml o f water or up to the individual c o n s t a n t sensation volume. We report the immediate

and early results o f this a m b u l a t o r y a p p r o a c h in order to illustrate the value d e f a e c o m e t r y m a y have in the treatm e n t o f these patients as well as in its objective assessment.

Patients and methods This study concerns 16 constipated patients presenting with anismus (F: 10 M: 6; mean age: 42.5 +_3.5 years). Patients were selected on anamnestic criteria and on the basis of physical examination, manometry, defaecometry, evacuation proctography and electromyography. Evacuation proctography and anal manometry confirmed the contraction of the striated sphincter during defaecation. Laborious or impossible defaecation was also documented by defaecometry. The electrical activity of the external anal sphincter increased during straining. Endocrine, pharmacologic, organic and neurologic causes of constipation were excluded. In three patients anismus was accompanied by prolonged left and right segmental colonic transit time as proven by radiopaque markers. Manometric and defaecometric data were also obtained from 10 control subjects (F: 5, M: 5; mean age: 44.5_+5.4 years). They were free of any clinical anorectal pathology at present or in the past and had normal bowel habits subjectively. Anal manometry was performed in the left lateral position with the rectum empty using the conventional water-filled microballoon technique [3]. The maximum anal basal pressure (MABP) and the squeeze pressure (MAC) were recorded using the station pullthrough technique. The rectoanal inhibitory reflex (RAIR) was induced by transient air insufflation of a balloon placed 8 cm above the anal margin. The minimum amount of insufflation required to induce maximum internal sphincter relaxation was called the maximum-fAIR-threshold. The pressure recorded at the level of the MABP after maximum internal sphincter relaxation was called the minimum residual pressure (MRP). The methodology of defaecometry, rectal compliance and pelvic sensation measurement in sitting position have been described elsewhere [30, 40]. A collapsed condom with two catheters (one recording the intra-balloon pressure while the other was used for water injection) was located just above the anorectal junction. Three microballoons were placed in the upper, middle and lower anal canal. The subject was seated on a commode. Pressure transducers were connected to a personal computer through an interface for storage and visualisation of the pressure phenomena on the screen. The rectal balloon was slowly filled with 50 ml of warmed water. The subject was asked to evacuate this simulated stool while left alone, after his/her normal squatting position was checked. Two consecutive defaecometries were performed in order to ascertain reproducibility. The act of evacuation was analysed by the maximum rectal pressure increase achieved, the duration and the work performed during the evacuation of the simulated stool. The performed work (in units) corresponds to the area under the rectal pressure curve from the beginning of the straining act until the evacuation of the balloon. The change of anal pressures was evaluated qualitatively only. After defaecometry with 50 ml, the physiology of normal defaecation and the pathophysiology of anismus were explained to the patients using their pressure recordings visualised on the PC screen. After eventual reinsertion of the condom, it was filled with warmed water at a rate of 60 ml/min until a constant desire for defaecation occurred. The rectal compliance (volume/pressure in ml/mmHg) was calculated at that sensation level. Patients were asked to bear down several times on this "faecal" bolus without excessive effort, while the anal pressure did not have to increase unduly, or, ideally, had to decrease. Real-time visualisation of anal and rectal pressures (visual reinforcement) and verbal reinforcement greatly facilitated understanding the pathophysiology and helped to avoid paradoxical striated sphincter contraction. Then, the patients were left alone and instructed to evacuate the balloon. The result was analysed together with the patients. If the trial was ineffective, training was considered to be impossible after the pa-

204 tient was given at least two chances. If the evacuation was effective, defaecometry was repeated with 50 ml. For home therapy the patients were asked to relax the sphincter apparatus during expulsion of the rectal contents and to avoid excessive straining. Conservative treatment introduced before training in all patients was not changed, but laxatives, enemas and especially digitation in order to initiate defaecation were strongly discouraged. All patients were reexamined after 6 weeks. Defaecometry with 50 ml was performed in order to evaluate the remaining effect of the training session. Defaecation parameters and sphincter action during evacuation of simulated stool observed before and after training are compared. Mean values and their standard error are presented. For statistical analysis of differences paired or unpaired 2-tailed Student t tests are used where appropriate.

Results

Immediate effect of a single training session Manometric and compliance data in controls and patients are summarized in Table 1. The M A B P was slightly but not significantly higher in constipated patients than in the controls. The R A I R was present in all cases. The maximum R A I R threshold as well as the amplitude of maximal internal sphincter relaxation were comparable, but the M R P was significantly higher in patients than in the controls. Constipated subjects needed slightly more volume and less pressure to achieve the constant sensaTable 1. Manometric data Controls N of patients MABP (mmHg) MAC (mmHg) Sphincter length (cm) RAIR present Max. RAIR Vol. (ml) RAIR Amplit. (mmHg) MRP (mmHg)

10

Constipated patients

p-value

16

66 • 4.5 161 +16 3.6_+ 0.2 10/10 61 -+ 4.6 43.2_+4.4 22.3-+ 4.3

78.5-+ 6.6 158 -+13.8 3.3_+ 0.2 16/16 55 -+ 4 44.8-t- 6.5 33.8+_2.6

NS NS NS

CS Rect. Vol (ml) 150 _+ 7 CS Rect. Pr. (mmHg) 29 __ 3 CS Rect. Co. (ml/mmHg) 5.7-+ 0.6

212 -+23 24 -+ 2 9.4_+ 0.9

NS NS 0.006

NS NS 0.02

MABP = maximum anal basal pressure; MAC = squeeze pressure; RAIR = recto-anal inhibitory reflex; MRP = minimum residual pressure; CS Rect. Vol. or Pr. or Co. = constant sensation rectal volume or pressure or compliance; NS = not significant

tion level. As a consequence, rectal compliance at that sensation level is significantly higher in patients than in controls (p = 0.006). Every control subject was able to evacuate a simulated stool of 50 ml, but 9/16 patients could not. Every patient, irrespective of the effectiveness of expulsion, had strong sphincter contraction during bearing down on the rectal balloon. This phenomenon was never observed in controls. Patients who could evacuate the simulated stool needed significantly longer duration (19= 0.004) and more work (p = 0.0001) than the controls, while their expulsion pressure was normal (Table 2). After explanation and filling the rectal balloon up to the individual constant sensation level, only 2 out of 16 patients were left who could not evacuate the larger bolus. Sphincter contraction during bearing down was observed in both of them but also in seven others who could evacuate the rectal balloon. A similar p h e n o m e n o n was never observed in controls, who all evacuated the larger volume slightly easier than the 50 ml balloon. In constipated patients who initially could expel a 50 ml balloon both the duration of evacuation (p = 0.0004) and the performed work (t7 = 0.006) were significantly facilitated by increasing the rectal balloon volume till their constant sensation level (Table 2). Defaecometry using a 50 ml balloon was performed again in those 14 patients who could expel a simulated stool at constant sensation. All but one could evacuate the smaller balloon (Fig. 1). Sphincter contraction did not occur in six patients. Thus, at the end of a single training session defaecation became significantly easier as compared with pretraining parameters in 11/16 patients: evacuation became effective in six cases and improved in five others.

Remaining effect 6 weeks after a single training session The manometric data, rectal compliance and sensation measurement remained unchanged. Seven patients could not evacuate the 50 ml simulated stool. However, improved defaecation was preserved in the nine others: the number of patients with initially ineffective expulsion decreased by two, while seven cases had easier defaecation than before training (Fig. 1). Moreover, seven out o f these nine patients had no sphincter contraction during bearing down on the rectal balloon. Subjective reports of the patients correlated perfectly

Table 2. Defaecometry parameters Rect. balloon vol.

Expulsion Sphincter contr, during defaec. Rect. pr. (mmHg) Duration (sec.) Work (U)

Constipated patients (n = 16)

Controls (n = 10)

Pre-training

At training session

50 ml

CS vol.

50 ml

CS vol.

50 ml

6 weeks after training 50 ml

10/10 0/10 78 +_13 7.3-+ 0.8 2.3 -+ 0.45

10/10 0/10 62 -+9.2 6.9 _+2.2 1.76 + 0.56

7/16 16/16 77 _+7.4 12.2 -+1.3 5.34-+0.63

14/16 9/16 71 +7 9.9 +1.1 3.55-+0.52

13/14 8/14 81 +9.4 9 -+1.2 3.55-+0.61

9/16 9/16 74.8 -+6.7 8.22-+1.1 2.9 -+0.38

205 a

5Oral

b

CS vol

... , .:.: 9 ...

5 ! / ~,~

c

50 ml

d

'. 9 .i

50ml

~ ........ . .........

~ 100mn~

.:::=

l 0 sec. Fig. 1. Pressure recording from a rectal balloon (condom) during its evacuation before (a), at (b, e) and 6 weeks after (d) a single training session. Initially the patient was unable to evacuate the balloon filled with 50 ml of water (a). After explanation and filling the balloon with water till the constant sensation (CS) level 200 ml in this case - an evacuation was performed rather easily (b). Immediately after this defaecometry using a 50 ml balloon was performed again without visual feedback from the manometric PC monitor; evacuation was possible though with somewhat more work (area under the curve) than with constant sensation volume (c). After 6 weeks the effect of training was preserved; defaecometry parameters even were within the normal range (d) with the results of defaecometry. A symptomatic recurrence of outlet obstruction type constipation was not observed in the nine patients with preserved training effect during a follow up period of at least 12 months. Among these nine patients were two out of the three subjects suffering from anismus accompanied by slow colon transit constipation; their defaecation became easier and more frequent.

Discussion

The result o f an adequately corrected rectocele or prolapse will remain perfect only when the possible predisposing factor, anismus, is cured as well. The aetiology of anismus remains unclear. Paradoxical anal sphincter muscle contraction may be part of the generalised extrapyramidal motor disorder in Parkinson's disease [41]. External sphincter contraction during straining has also been observed in one-third of the control subjects in one series [42]. In contrast, we have never found sphincter contraction during defaecation in sitting position [30]. This highlights the difficulties of determining what constitutes normality and thus, how to select control subjects. Patients suffering from anismus have a moderately higher basal tone than controls. This can be explained by an increased MRP, since the amplitude of the maximal

internal sphincter relaxation was normal. The M R P is mainly related to the tonic activity of the striated perianal musculature, at least when measured with small diameter probes [43]. Therefore, these manometric findings indicate that the striated sphincter activity is increased not only during defaecation but also at rest. In contrast, the internal sphincter functions normally: its contribution to the anal basal tone is normal and it can be fully relaxed. Our observations do not support previous hypotheses suggesting that this condition is the result o f a decreased ability of the internal sphincter to relax with rectal distension [1, 44]. A decreased percentage of anal pressure reduction during a R A I R of maximum amplitude can be explained by an increased M R P related to striated muscle hyperactivity. The rectal compliance was found to be increased. Others have reported an impaired rectal constant sensation [13, 27, 45]. The threshold of rectal distension to induce a maximum RAIR, however, was normal. An identical phenomenon was observed in constipated children [45]. This indicates that the viscoelastic properties of the rectum can be disturbed without involvement of the receptors inducing an internal sphincter relaxation. Although our findings do not explain the aetiology of the disordered defaecation in anismus, they confirm that the pathology is limited to the striated pelvic floor musculature. Therefore, the treatment of anismus has to be targeted on the puborectalis muscle and the external sphincter. Our biofeedback approach is based on the visualisation of the patient's anorectal pressures on the screen of a personal computer during evacuation of a simulated stool placed just above the anorectal junction. Moreover, we applied the physiological observation of easier evacuation of a large rectal bolus [39], expecting that this would make simulated defaecation easier in patients suffering from anismus. The positive experience in evacuating the rectal contents also could reassure these patients. Thus, training was performed with a balloon filled with water up to the constant sensation level. Expulsion became possible in 7/9 patients who could not evacuate a 50 ml balloon initially and made the defaecation much less laborious in the others. Cortical suppression of the striated sphincter activity also was facilitated during bearing down in those circumstances: paradoxical contraction of the striated sphincter musculature was immediately corrected in 7/16 cases. Therefore, we feel that this method of defaecation training has many methodological and physiological advantages as compared with biofeedback sphincter training using an anal plug, needle or surface electrode eventually performed in the absence of constant rectal sensation or in a lying position. It is interesting that patients were able to expel a larger balloon and this suggests that there may be a sensory problem, causing the inappropriate contraction during defaecation. Although the normal stool volume is reported to be 120 g/day [46], we judged that training also had to result in an improved evacuation of a smaller bolus. Therefore, we maintained the 50 ml rectal bolus originally used in the defaecometry test. As an immediate and objective benefit o f training, the number o f patients who originally could not evacuate a 50 ml bolus decreased, while defaecation work significantly decreased in those who could.

206 Nevertheless, we feared that the beneficial effect of a single training session might soon vanish. After 6 weeks, however, the benefit of the single training session was preserved in 9 out of 14 patients. Our data confirm that learning normal defaecation dynamics is correlated with clinical recovery [47]. We also found a very good correlation between the symptomatic result, improved defaecation dynamics and defaecometry data. This is in contrast with the findings of others that balloon defaecation did not improve significantly in those who learned normal defaecation dynamics [47]. This may be related to methodological factors: type and level of the balloon, nature and volume of its contents, method of analysis. But we can confirm that anismus patients unable to evacuate balloons are much more difficult to train than patients able to perform a simulated defaecation. A n analogous observation has been reported in constipated children after conventional laxative and "bowel training" treatment [25, 48]. Globally our "cure rate" of 9/16 cases is comparable with data from the literature reporting good results after biofeedback training of anismus patients in 6 0 - 1 0 0 % [10, 13, 25, 26, 28, 29, 38, 47]. In conclusion, we feel that retrospective data about defaecation are unreliable. They should be checked and quantified by defaecometry and investigated by evacuation proctography. Symptomatic treatment of constipation will fail in patients with anismus because it does not treat the cause, except when it is due to hard and small scyballous stool. Anal pain should also be treated first or at least concomitantly with biofeedback training. Biofeedback is the treatment of choice and there is no major place for surgery in anismus. We have elaborated a new biofeedback approach integrating simulated balloon defaecation with small (50 ml) and constant rectal sensation volume, defaecometry and anal manometry. Examination and training take about 2 to 3 hours, which, in our opinion, is a very acceptable effort whereby the majority of these patients can be helped. Although our method of biofeedback defaecation training does not work in every patient, especially in those with "blind" rectum, we are convinced it is a simple and valuable alternative to other types of biofeedback training for anismus. We are further assessing its performance in our clinical practice. In the last year, 29 patients have been trained. Normalisation of defaecation parameters was obtained in 11 cases, two could not be trained and defaecation significantly improved but did not normalise in the others. After 6 weeks the benefit of training was preserved in the majority of the patients, although the effect was completely lost in 2/17 cases controlled so far.

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Professor Dr. E Penninckx University Clinic Gasthuisberg Department of Abdominal Surgery Herestraat 49 B-3000 Leuven Belgium