CORRELATION BETWEEN ANORECTAL MANOMETRIC FINDINGS AND CLINICAL OUTCOME IN PATIENTS OPERATED FOR HIRSCHSPRUNG'S DISEASE
H.R. Forootan, S.A. Banani, A. Bahador, N. Nezakatgoo
Division of Pediatrics Surgery, Department of Surgery, Shiraz University of Medical Sciences, Shiraz, Iran
ABSTRACT In order to identify a possible correlation between anorectal manometry (ARM) findings and clinical outcome in patients operated for Hirschsprung's disease (HD), ARM was performed on 58 patients 4-9 years after operation. In relation to bowel habits, three different clinical categories were defined. Normal bowel movement was present in 39 (67%) patients (Group I). Fourteen (24%) patients had frequent soiling and were considered incontinent (Group II). The remaining five (8.6%) cases had constipation (Group III). ARM in group I revealed normal tone (10-40 mm Hg) in 21 (53.8%) and increased tone (>40 mm Hg) in the remaining 18 patients. Seven out of 14 (50%) of group II patients had markedly decreased anal tone (<10 mm Hg), while all five patients with constipation had increased tone. The mean anal sphincter tone in group II was significantly lower than that of groups I and III (p < 0.05). Furthermore, while rectoanal reflex (RAR) was present in about one third of patients in group I, it was absent in patients of group III. This reflex, however, could not be evaluated because of the very low tone in the soiling group. In conclusion, the majority of patients with HD had normal bowel movement after surgery along with normal or increased internal sphincter tone. Although most of these patients showed lack of relaxation, which has no diagnostic value, the presence of RAR may have a predictive value, since it is frequently associated with fecal continence. Moreover, although high tonicity was not correlated with clinical status, markedly decreased anal tone was almost always associated with incontinence. Therefore, to make a proper decision for further management, the clinical status of the patient's bowel habit should be interpreted in the light of ARM findings.
Irn J Med Sci 1997; 22(3 & 4):108.
Introduction
Anorectal manometry (ARM) is one of the important diagnostic tools in many ano-rectal problems including Hirschsprung's disease (HD).12,18,19
The first physiological studies in patients with congenital megacolon were described by Swenson23 in 1949 and Hiatt7 in 1951. The characteristic behavior of aganglionic segment and internal sphincter were shown by Conell3 and Fontaine.4 Subsequently, Holschneider-Koepke9and also Nixon16 described these findings in patients with HD. Although some investigators have performed ARM in these patients post- operatively,6,8,14-16 a definite correlation between ARM findings and the clinical outcome has not yet been achieved. In this study, a correlation between degree of clinical continence and that of anal sphincter tonicity and also the importance of the presence or absence of internal sphincter relaxation has been addressed.
Materials and Methods
The charts of 132 patients, who had undergone definite procedure for HD from September 1983 till August 1993, were reviewed. After an adequate follow-up of at least four years, these patients were asked to refer for clinical evaluation of bowel habits and also performance of ARM. Fifty-eight patients with different pull-through procedures referred for the assessment (Table 1). Normal spontaneous bowel movement without soiling or infrequent soiling was regarded as normal defecation. Constipation was defined as dry perineum or occasional soiling but lack of bowel movement for more than 48 hours. Those with frequent intermittent soiling (more than three episodes per day) were considered incontinent. Manometric studies were performed with a probe perfused at a rate of about ten drops perminute and the pressure recorded by Martin Gruber manometry device. Internal anal sphincter tone (IST) was measured and rectoanal reflex (RAR) was checked in response to dilatation of the rectum following Foley catheter inflation. Ice saline irrigation was used for detection of the reflex in those with non-specific findings. RAR was assumed positive when a significant fall (>50%) was obtained after at least 3 consecutive balloon stimulations, with a certain latency (lag period of 3-4 seconds). Statistical analyses were performed by one way ANOVA, Duncan procedure and Fisher exact test.
Results
Forty-two out of 58 patients (75%) who referred for clinical and manometric evaluation were male. Mean age of the whole group was 4.5 years, with a follow-up period of 4 to 9 years. In relation to bowel habits, three different clinical situation were observed. Normal bowel movement was present in two third of the patients (39/58 =67%) (Group I). Fourteen patients (24%) were suffering from frequent intermittent soiling and were considered incontinent (none being totally incontinent)(Group II), while five patients (8.6%) remained constipated (Group III).
Twenty-one out of 39 patients (53.8%) in group I had normal anal tone (10-40 mmHg),while the tone was increased (>40 mmHg) in the remaining 18 (46%) patients (Table 2). The latter situation (increased tone) was observed in all 5 patients in G III. However, the anal tone was significantly decreased (<10mmHg) in 7 of 14 patients (50%) in G II, while it was increased in 3 other patients (22%) of the same group. If quantitatively interpreted, the average anal tone in incontinent patients was significantly lower than the other two groups (25.14±19.97 vs 35.76±13.74 and 48±2.73 mmHg; P<0.05). Moreover, if the clinical state of incontinence vs continence is correlated with the low IST (less than 10 mmHg), the statistical difference between these two situations would be much more significant (7/14 vs 0/39, P<0.00003). On the other hand, no significant difference was observed between continent and constipated patients (Table 2).
RAR was present in only 30% (12/39) of patients in group I. It was, however, absent in all of the constipated patients. Nonetheless, this difference was not statistically significant. Because of the very low anal tone, assessment of the RAR was not possible in 7 (50%) of 14 patients in the incontinent group. Nevertheless, this reflex was detected in 3 of the remaining 7 patients in the same group, all of whom had normal internal sphincter tone. Nonspecificrelaxation was detected in 7 patients; six with normal bowel movement and one with frequent soiling (incontinent) (Table 3).
Discussion
Because of its simplicity, non-invasiveness and accuracy, ARM has been widely used for several decades as a screening test for evaluation of patients with chronic constipation particularly for diagnosis of HD.12,18,19 ARM has also been used for evaluation of continence and response to biofeedback therapy after repair of imperforate anus and also investigating the degree of improvement following management of chronic constipation.1,11 However, only a few reports have been published concerning application of ARM in evaluation of Hirschsprung patients after surgery.6,8,14-16
Successful results with favorable outcome after definitive surgery for HD are variable, ranging from 30% to 94%.14,15 Heig, et al. believe this difference may be due to different operative techniques or the tools by which the success rate is evaluated.5 Detailed history, physical examination, manometry, profilometry, endosonography or colonic transit time may detect more of anorectal function impairment.5 Although some contend that anorectal functiondoes not improve with time5,14, Nagasaki, et al. report that some improvement may be achieved in 2-3 years after operation.17 When evaluated 4-9 years after operation, 67% of our patients had normal bowel movement.
While in some series, the initial method of pull-through procedure has had no effect on the manometric findings6, in others, however, the magnitude of IST has been shown to depend on the type of operation14 (lower tone in modified Duhamel and higher tone in endorectal pull- through procedure).14 Holschneider found a normal sphincter tone in 30-50% of his patients.8 Similarly, normal IST (10-40mmHg) was present in 44% (25/58) in our series. Having correlated continence and the anal tone, 84% of our patients (21 out of 25) with normal tone were continent (Table 2). Moreover, not only did all constipated patients have increased IST, but 18 of 39 patients (46%) with normal bowel movement also showed the same manometric findings (tone>40mmHg). On the contrary, decreased IST (<10mmHg) was observed only in those with frequent soiling, while none of the continent patients had low IST (P<0.00003). Similarly, Nagasaki, et al.17 have also concluded that high tone is found in constipated patients and low tone in those who were incontinent. However, this conclusion has not been accepted by other investigators.8,14,15 The results of our series indicate that, although increased tone is not definitely correlated with clinical outcome, since it was seen in all three groups with different frequencies, marked decreased tone was almost always associated with incontinence. In other words, if a low IST is encountered post-operatively, the chance of having frequent soiling, though not totally incontinent, remains a high possibility. In addition, the majority of patients with normal tone are usually continent. There has also been a positive correlation, in Heikkinen, et al.'s studies, between functional outcome and resting pressure in adults operated for HD during early childhood.6
RAR has been reported variably in different series ranging from 0-100%.6,14,16,19,22 Compared to Holschneider series in which two third of the patients had internal sphincter relaxation8, this was the case in only 26% of our patients. However, had the nonspecific reflexes been taken into account, this figure would have been higher. The variation in different series might have been related to the various types of pull- through procedures; RAR is present more often after modified Duhamel procedure, less frequent following endorectal pull-through (Soave or Boley) and least after Swenson operation.8,14 This phenomenon could be explained on the basis of radicality of the procedure whichincludes partial internal sphincterotomy, usually performed in modified Duhamel technique.8,10 Nevertheless, this reflex, in spite of different procedures (including Duhamel in majority), has been negative in all patients in Heikkinen, et al. series.6
Ultimately, definite correlation between presence or absence of RAR and normal bowel movement has not yet been established and remains controversial.6,8,14-16,22 Nagasaki. et al, found out that 91% of their patients with normal bowel movement had positive RAR, while this reflex was present in only 25% of their constipated patients.16 Moreover, incontinent patients in that report had low IST, of whom only 20% had positive RAR.16 Suzuki, et al. also reported that RAR was present in the majority of patients treated with the Kasai rectal myotomy coupled with colectomy and in all patients following Lynn's rectal myectomy.21 Comparatively, only fifteen patients (26%) in our report had normal relaxation, 12 (80%) of whom were continent and the remaining 3 had frequent soiling. On the other hand, of the 29 patients with no relaxation, 21(72%) had normal bowel movement. Therefore, according to our results, the majority of patients with normal bowel habit do not show relaxation. Furthermore, this reflex is not usually observed in constipated or incontinent patients having too high or too low tonicity, respectively. Nevertheless, in spite of presence of RAR in 30% of continent patients, when compared to constipated group with no RAR, the difference is not significant (P=0.131). Conclusively, although absence of RAR has no diagnostic value, but its presence is most probably a good prognostic factor, as it is frequently associated with fecal continence. Ultimately, if a definite conclusion for proper decision and further management is to be achieved, one should correlate the clinical state of the patient's bowel habit to the ARM findings.
Constipation is one of the most frequent and disappointing complications after pull-through operation.2,20 Having excluded the anatomicallesions (stenosis, retraction, etc), anal achalasia is the most common functional cause.2,20 The latter situation can easily be identified by ARM, showing high anal tone and lack of relaxation.2,20 Once proven to be refractory to medical therapy, this problem can usually be overcome by posterior anorectal myectomy2,20,24 or internal sphincter myectomy.14 Therefore, to prevent recurrence of symptoms due to anal achalasia following definitive procedures, internal sphincter should be adequately weakened during the pull-through operation.20 For that reason, an internal sphincterotomy in Duhamel10 or Swenson technique and Marks' operation (posterior sagittal rectal split)13 extending to the mid-anal canal in endorectal pull-through procedure is highly recommended.
References
1 Ahran p, Faverdin C, et al: Manometric assessment of continence after surgery for imperforate anus. J Pediatr Surg 1976; 11: 157-166.
2 Banani SA, Forootan HR: Role of anorectal myectomy after failed endorectal pull-through in Hirschsprung's disease. J Pediatr Surg 1994; 29: 1307-1309.
3 Conell AM: The mortality of the pelvic colon, part II: paradoxical motility in diarrhea and constipation. Gut 1962; 3: 342-346.
4 Fontaine J, Reuse JJ, et al: Analysis of the peristaltic reflex in vitro: effects of some endogenous transmitters. Arch Int Pharmacodyn 1973; 206: 371-375.
5 Heij HA, de Vries X, et al: Long-term anorectal function after Duhamel operation for Hirschsprung's disease. J Pediatr Surg 1995; 30: 430-432.
6 Heikkinen M, Rintala R, et al: Long-term anal sphincter performance after surgery for Hirschsprung's disease. J Pediatr Surg 1997; 32: 1443-1446.
7 Hiatt RB: The surgical treatment of congenital megacolon. Ann.Surg 1951; 133: 321-324.
8 Holschneider AM: Post-operative manometric findings, in: Holschneider AM (ed): Hirschsprung's disease. New York, NY, Thieme, 1982; 235-240.
9 Holschneider AM, Koepke V: Was leistet die Elektromanometric in der Diagnostik anorectaler Erkrankungen? Ein diskriminanzanalytische studie. Z Kinderchir 1975; 16: 411-414.
10 Hung WT: Treatment of Hirschsprung's disease with a modified Duhamel-Grob-Martin Operation. J Paediatr Surg 1991; 26: 849-852.
11 Ishihara and Morita: Continence and reflex pressure profile after surgery to correct the imperforate anus. Prog Pediatr Surg 1989; 24: 86-96.
12 Lawson JON, Nixon HH: Anal canal pressure in the diagnosis of Hirschsprung's disease. J Pediatr Surg 1967; 2: 544-552.
13 Marks RM: Endorectal split sleeve pull-through procedure for Hirschsprung's disease. Surg Gynecol Obstet 1972; 136: 627-628.
14 Mishalany HG, Woolley M: Postoperative functional and manometric evaluation of patients with Hirschsprung's disease. J Pediatr Surg 1987; 22: 443-446.
15 Moore SW, Millar AJW, et al: Long-term clinical, manometric, and Histological evaluation of obstructive symptoms in the postoperative Hirschsprung's disease. J Pediatr Surg 1994; 29: 106-111.
16 Nagasaki A, Ikeda K, et al: Postoperative sequential anorectal manometric study of children with Hirschsprung's disease. J Pediatr Surg 1980; 15: 615-619.
17 Nagasaki A, Sumitomo K, et al: Anorectal manometry after Ikeda's Z-shaped anastomosis in Hirschsprung's disease. Prog Pediatr Surg 1989; 24: 49-58.
18 Schnaufer L, Talbert JL, et al: Differential sphincteric studies in the diagnosis of ano-rectal disorders of childhood. J Pediatr Surg 1967; 2: 538-543.
19 Schuster MM, Hendrix TR, et al: The internal anal sphincter response: Manometric studies on its normal physiology, neural pathways and alteration in bowel disorders. J Clin Invest 1963; 42: 196-207.
20 Soave F: Endorectal pull-through: 20 years experience. J Pediatr Surg 1985; 20: 568-579.
21 Suzuki H, Tsukamoto Y, et al: Motility of anorectum after rectoplasty with posterior triangular flap in Hirschsprung's disease. J Pediatr Surg 1984; 14: 335-338.
22 Suzuki H, Watanabe K, et al: Manometric and cineradiographic studies on anorectal motility in Hirschsprung's disease before and after surgical operation. Tohoku J Exp Med 1970; 102: 69-80.
23 Swenson O, Neuhauser EBD: New concept of the etiology and diagnosis and treatment of congenital megacolon. Pediatrics 1984; 4: 201-204.
24 Yoshioka, Keighley M: Anorectal myectomy for outlet obstruction. Br J Surg 1987; 74: 373-376.