Anterior Anal Sphincter Repair Can Be Of Long Term Benefit: A 12-Year Case Cohort From A Single Surgeon

Benjamin R Grey; Rowena R Sheldon; Karen J Telford; Edward S Kiff


BMC Surg 

In This Article

Discussion and Conclusion

Anal sphincter defects are a common cause of faecal incontinence, with obstetric injuries in female patients accounting for the majority.[15] The results from previous studies[4,5] show that early postoperative success is achieved in 70-90% of cases. Longer term results have showed lower success rates.[2,11] It remains unclear why we see a time related deterioration in clinical outcome after an initially successful sphincteroplasty. The true extent of the injury, as detected by endoanal ultrasound and more recently magnetic resonance imaging, may not be appreciated at the time of sphincteroplasty. Occult co-existent anatomical defects of the pelvic floor may contribute to poor long term outcome.[16,17] Ageing, with resulting atrophy of striated muscle, may also play a part.[18] Furthermore overzealous repairs may actually denervate or devascularise the EAS with subsequent poor outcome.

The questionnaire response rate for the study is disappointing. We report on a single surgeon's tertiary referral practice from three regions. It should be recognized that on re-contacting patients, following discharge from our care, their correspondence addresses may have changed. We can only speculate as to whether the non-responders had positive or negative results from their surgery.

In this study, 96% of patients reported an excellent initial improvement in symptoms. Of the 47 patients assessed long term (≥ 5 years), 28 (60%) maintained a good outcome. All patients underwent a standardised surgical repair and there was no difference between any subgroups of patients, yet for 40% of patients a long term successful outcome was not achieved.

There is no correlation between preoperative anorectal physiology investigations and successful outcome. However, in the five patients who went on to have colostomies fashioned following failed ASR surgery, a trend towards lower preoperative resting and voluntary contraction pressures was noted.

Previous studies looking at anorectal manometry investigations have reported conflicting results[19,20] following anterior sphincter repairs, however most studies report improvement in manometry in successful patients. Interestingly postoperative anorectal physiology in our patients revealed no improvement in resting or voluntary contraction pressures. Repairing the sphincter defect does not appear to alter the function of the striated EAS. Surgery may however have a stenosing effect and alter the compliance and length of the anal canal thus contributing to improved anal continence. Patients undergoing sphincter repair had an improved outcome success if they had a defect in both sphincters, internal and external as opposed to just an external sphincter defect (p = 0.001), the numbers however are small.

The St Mark's scores suggested that complete continence, and therefore cure, was not being achieved, however significant improvements in quality of life were demonstrated.

In this study group 32% of patients had unilateral or bilateral pudendal neuropathy diagnosed by PNTML measurement. This incidence is similar to that of a larger unselected group of 2067 patients previously published by our group.[21]

Our study, like others[22] has shown that the long term outcome of sphincteroplasty does not appear to be affected by pudendal neuropathy determined by PNTML measurement. In light of this we propose that sphincteroplasty should be performed for sphincter defects despite the presence of pudendal neuropathy.

Changes in shape, length or distensibility of the sphincter may be occurring. At our unit a levatoroplasty is routinely performed. Anal sphincter repair and levatoroplasty may promote the formation of scar tissue promoting a more rigid, less distensible anal canal. These changes may be responsible for the improvement in symptoms reported.

Anterior sphincter repair with levatoroplasty is successful in improving symptoms of faecal incontinence. Even if all the non-responders had a poor result then for one third of patients this procedure remains worthwhile in the long term.


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