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Surgery of anorectal incontinence
THE LA_NCET
Surgery of anorectal incontinence Norman S Williams Faecal incontinence is a far more common problem than is generally appreciated and it is not confined just to elderly people. The prevalence rate among individuals aged above 15 years has been reported to be 4.3 per 1000 population, 1 but this figure is likely to be a considerable underestimate. Incontinence is not a subject that patients and doctors are comfortable discussing, so it receives little media exposure. Hence, there is ignorance about the considerable progress that has been made in the understanding of anorectal physiology, which has paved the way for improvements in therapy. Since a colostomy is still commonly perceived to be the only procedure available for this distressing disorder, only a small proportion of patients are referred to appropriate specialist units. Stomas
to accommodate a catheter of sufficiently large diameter for successful irrigation of the adult colon. To combat this design fault, an alternative technique is to fashion a colonic conduit from the ascending colon; the conduit contains an intussuscepted valve, which prevents reflux of colonic contents onto the abdominal walP (figure 1). Some children have had their appendicostomy replaced by a conduit, and selected adult incontinent patients whose main problem has been difficulty in rectal emptying have undergone this procedure as a primary operation. Despite the success of these methods of colonic irrigation, the preference for both children and adults is avoidance of any opening on the abdominal wall that needs instrumentation. For some patients this option can now be realised. Neosphincters
Anorectal incontinence The commonest cause of affects all ages. About 500 incontinence among women babies a year are born in the is childbirth. Sultan et aP U K with anorectal agenesis, found that 13 % of which requires either a primigravidae and 23% of colonic pull-through multigravidae had some procedure or, more degree of incontinence in the first 6 weeks after delivery, commonly, a posterior and MacArthur et al 8 saggital anorectoplasty, 2 reported that up to 2 years which restores normal later 4% still had the anatomy but commonly leaves the child incontinent. symptom. Physiological Although the incontinence study by use of manometry, may not be such a problem sphincter electromyography, in the early years, it is quite and endoluminal ultrasonography will generally reveal devastating when the child Figure 1: Colonic conduit for antegrade colonic enema (ACE). the cause. Thus a defect in reaches school age and is the external sphincter can be identified by endo-anal even worse during adolescence. Paediatric surgeons have uhrasonography, and a long pudendal-nerve latency is tried to overcome the problem by devising a simple yet indicative of a neuropathy. Provided the external sphincter ingenious operation known as an antegrade colonic enema defect is an isolated abnormality, direct sphincter repair (ACE) procedure? In this operation the appendix is usually gives excellent results, even if the procedure is detached from the caecum, isolated on its mesentery, then delayed many years after the original injury. However, reversed and reattached to the caecum by being buried in problems are encountered if the defect is extensive, if a tunnel in the wall. The end that was previously attached the internal anal sphincter is also damaged, if a to the caecum is then exteriorised through a tiny aperture neuropathy co-exists, or if a direct sphincter repair fails. in the abdominal wall. This appendicostomy allows the The likelihood of extensive sphincter damage is increased child to intubate the proximal colon regularly and irrigate in iatrogenic incontinence--for instance, after haemothe colon in a distal direction to clear it out and to keep it rrhoidectomy or fistula surgery. In such circumstances a empty between irrigations. neosphincter can now be constructed. Although this procedure has proved a success for many There are basically two types of neosphincter--one is children, a substantial proportion dislike irrigating the made with the patient's own skeletal muscle, usually the colon. In addition, as the child grows, the channel through gracilis, 7"8and the other consists of a silastic cuff connected which the catheter is passed commonly proves too narrow to a fluid-filled reservoir that allows the cuff to be inflated Lancet 1999; 3 5 3 (suppl I): 31-32 around the anal canal to occlude it. 9 I cannot disguise my preference for the gracilis muscle version, because of my Academic Department of Surgery, St Bartholomew's and Royal involvement in its development. Nevertheless, this bias is London School of Medicine ad Surgery, London E1 1BB, UK (Praf N S Williams, FRCS) based on a belief backed by experience in animal Surgery • Vol 353 • April ° 1999
sI3 1
THE LANCET
Figure 2: Electrical stimulation of gracilis neosphincter.
experimentation that any foreign body placed in intimate contact with the bowel will eventually erode into the lumen if it does not become infected first. Nevertheless, some investigators have reported success. Thus, Lehur et al implanted 14 AMS 800 artificial sphincters (American Medical Systems, Minneapolis) in 13 patients. Nine patients were subsequently found to be continent for stool and five were continent for gas. However, sepsis occurred in two patients, and the device had to be removed from three. There can also be mechanical failure, as illustrated by another patient, in whom the cuff needed replacement because of rnpture. To create the gracilis neosphincter, the muscle is mobilised from the thigh and transposed around the anal canal, either to surround the defective native sphincter or to replace it. The gracilis is then connected to a subcutaneously placed electronic generator akin to a cardiac pacemaker via an intramuscular or neural lead. The transposed muscle is then programmed to be stimulated continuously until it is converted from a fasttwitch fatiguable muscle to a slow-twitch non-fatiguable muscle capable of sustaining occlusion of the anal canal. When the patient wishes to empty the rectum, the neosphincter is relaxed by use of a hand-held
si32
radiotelemetry device (figure 2) to turn the pacemaker off. A refinement of the current technique allows the handheld device to increase the contractile force of the neosphincter (within limits set by the power of the stimulator) so that the patient can withstand exceptional threats to continence. Initial studies suggested 60-65% success rates in severely incapacitated patients, many of whom had undergone a previous repair. 7,s Since 1988, approximately 500-1000 of these operations have been done in the USA and Europe. The technique is now the subject of a 20-25 centre study in the USA and a similar but yet more modest worldwide study is about to be published. In England in 1997 the National Specialist Commissioning Advisory Group (NSCAG) set up an external assessment of the technique as done at the Royal London Hospital. N S C A G fund 20-30 procedures per year and the project is scheduled to finish in 2002. At that time, if the procedure is deemed to be successful, it will be designated as a supraregional service, and a decision will be taken as to how many other centres will be required to provide a national service. The challenge is obviously to improve previous results. There have been improvements in the reliability of the hardware, which was a particular problem in the early years. 1° Further success is likely to be achieved by seeing patients at an early stage in their disease, by understanding that many patients have an underlying rectal sensory abnormality, by using advanced physiological measurements to select patients, and by finding a solution to the impaired rectal evacuation that can mar the result in up to 25% of patients. Meanwhile affected individuals need to be made aware of the existence of techniques that avoid a permanent stoma. References 1 T h o m a s T M , Egan M, Walgrave A, Meade T W , The prevalence of faecal and double incontinence. Community Med 1984; 6: 216-20. 2 Pena A, de Vries PA. Posterior saggital anoectoplasty: important technical considerations a n d new applications. J Paed Surg 1982; 17: 796 809. 3 Malone PS, Ransley PG, Kiely EM. Preliminary report: the antegrade continence enema. Lancet 1990; 3 3 6 : 1 2 1 7 - 1 8 . 4 Williams NS, Hughes SF, Smchfield B. Continent colonic conduit for rectal evacuation in severe constipation. Lancet 1994; 343: 1321-24. 5 Sultan AH, K a m m MA, H u d s o n CN, Bartram CI. T h i r d degree obstetric anal sphincter tears: risk factors a n d outcome of primary repair. BMJ 1994; 3 0 8 : 8 8 7 - 9 1 . 6 MacArthur C, Bick DE, Keighley MRB. Faecal incontinence after childbirth. BrJ Obstet Gynaecol 1997; 104: 46-50. 7 Williams NS, Patel J, George BD, Hallan RI, Watkins ES. Development of an electrically stimulated neoanal sphincter. Lancet 1991; 3 3 8 : 1 1 6 6 - 6 9 . 8 Baeten CG, Geerdes BP, Adang EM, et al. Anal dynamic graciloplasty in the treatment of intractable fecal incontinence. N Engl JMed 1995; 332: 1600-05. 9 Lehur PA, Micho~: F, Denis P, et al. Results of artificial sphincter in severe anal incontinence: report of 14 consecutive implantations. Dis Colon Rectum 1996; 39: 1352-55. 10 M a n d e r BJ, Wexner SD, Keighley MRB, et al. The electrically stimulated gracilis neoanal sphincter: preliminary results of a multicentre trial. BrJ Surg 1997; 84(Suppl 1): 39.
Surgery • Vol 353 • April ° 1999
Surgery of anorectal incontinence Norman S Williams Faecal incontinence is a far more common problem than is generally appreciated and it is not confined just to elderly people. The prevalence rate among individuals aged above 15 years has been reported to be 4.3 per 1000 population, 1 but this figure is likely to be a considerable underestimate. Incontinence is not a subject that patients and doctors are comfortable discussing, so it receives little media exposure. Hence, there is ignorance about the considerable progress that has been made in the understanding of anorectal physiology, which has paved the way for improvements in therapy. Since a colostomy is still commonly perceived to be the only procedure available for this distressing disorder, only a small proportion of patients are referred to appropriate specialist units. Stomas
to accommodate a catheter of sufficiently large diameter for successful irrigation of the adult colon. To combat this design fault, an alternative technique is to fashion a colonic conduit from the ascending colon; the conduit contains an intussuscepted valve, which prevents reflux of colonic contents onto the abdominal walP (figure 1). Some children have had their appendicostomy replaced by a conduit, and selected adult incontinent patients whose main problem has been difficulty in rectal emptying have undergone this procedure as a primary operation. Despite the success of these methods of colonic irrigation, the preference for both children and adults is avoidance of any opening on the abdominal wall that needs instrumentation. For some patients this option can now be realised. Neosphincters
Anorectal incontinence The commonest cause of affects all ages. About 500 incontinence among women babies a year are born in the is childbirth. Sultan et aP U K with anorectal agenesis, found that 13 % of which requires either a primigravidae and 23% of colonic pull-through multigravidae had some procedure or, more degree of incontinence in the first 6 weeks after delivery, commonly, a posterior and MacArthur et al 8 saggital anorectoplasty, 2 reported that up to 2 years which restores normal later 4% still had the anatomy but commonly leaves the child incontinent. symptom. Physiological Although the incontinence study by use of manometry, may not be such a problem sphincter electromyography, in the early years, it is quite and endoluminal ultrasonography will generally reveal devastating when the child Figure 1: Colonic conduit for antegrade colonic enema (ACE). the cause. Thus a defect in reaches school age and is the external sphincter can be identified by endo-anal even worse during adolescence. Paediatric surgeons have uhrasonography, and a long pudendal-nerve latency is tried to overcome the problem by devising a simple yet indicative of a neuropathy. Provided the external sphincter ingenious operation known as an antegrade colonic enema defect is an isolated abnormality, direct sphincter repair (ACE) procedure? In this operation the appendix is usually gives excellent results, even if the procedure is detached from the caecum, isolated on its mesentery, then delayed many years after the original injury. However, reversed and reattached to the caecum by being buried in problems are encountered if the defect is extensive, if a tunnel in the wall. The end that was previously attached the internal anal sphincter is also damaged, if a to the caecum is then exteriorised through a tiny aperture neuropathy co-exists, or if a direct sphincter repair fails. in the abdominal wall. This appendicostomy allows the The likelihood of extensive sphincter damage is increased child to intubate the proximal colon regularly and irrigate in iatrogenic incontinence--for instance, after haemothe colon in a distal direction to clear it out and to keep it rrhoidectomy or fistula surgery. In such circumstances a empty between irrigations. neosphincter can now be constructed. Although this procedure has proved a success for many There are basically two types of neosphincter--one is children, a substantial proportion dislike irrigating the made with the patient's own skeletal muscle, usually the colon. In addition, as the child grows, the channel through gracilis, 7"8and the other consists of a silastic cuff connected which the catheter is passed commonly proves too narrow to a fluid-filled reservoir that allows the cuff to be inflated Lancet 1999; 3 5 3 (suppl I): 31-32 around the anal canal to occlude it. 9 I cannot disguise my preference for the gracilis muscle version, because of my Academic Department of Surgery, St Bartholomew's and Royal involvement in its development. Nevertheless, this bias is London School of Medicine ad Surgery, London E1 1BB, UK (Praf N S Williams, FRCS) based on a belief backed by experience in animal Surgery • Vol 353 • April ° 1999
sI3 1
THE LANCET
Figure 2: Electrical stimulation of gracilis neosphincter.
experimentation that any foreign body placed in intimate contact with the bowel will eventually erode into the lumen if it does not become infected first. Nevertheless, some investigators have reported success. Thus, Lehur et al implanted 14 AMS 800 artificial sphincters (American Medical Systems, Minneapolis) in 13 patients. Nine patients were subsequently found to be continent for stool and five were continent for gas. However, sepsis occurred in two patients, and the device had to be removed from three. There can also be mechanical failure, as illustrated by another patient, in whom the cuff needed replacement because of rnpture. To create the gracilis neosphincter, the muscle is mobilised from the thigh and transposed around the anal canal, either to surround the defective native sphincter or to replace it. The gracilis is then connected to a subcutaneously placed electronic generator akin to a cardiac pacemaker via an intramuscular or neural lead. The transposed muscle is then programmed to be stimulated continuously until it is converted from a fasttwitch fatiguable muscle to a slow-twitch non-fatiguable muscle capable of sustaining occlusion of the anal canal. When the patient wishes to empty the rectum, the neosphincter is relaxed by use of a hand-held
si32
radiotelemetry device (figure 2) to turn the pacemaker off. A refinement of the current technique allows the handheld device to increase the contractile force of the neosphincter (within limits set by the power of the stimulator) so that the patient can withstand exceptional threats to continence. Initial studies suggested 60-65% success rates in severely incapacitated patients, many of whom had undergone a previous repair. 7,s Since 1988, approximately 500-1000 of these operations have been done in the USA and Europe. The technique is now the subject of a 20-25 centre study in the USA and a similar but yet more modest worldwide study is about to be published. In England in 1997 the National Specialist Commissioning Advisory Group (NSCAG) set up an external assessment of the technique as done at the Royal London Hospital. N S C A G fund 20-30 procedures per year and the project is scheduled to finish in 2002. At that time, if the procedure is deemed to be successful, it will be designated as a supraregional service, and a decision will be taken as to how many other centres will be required to provide a national service. The challenge is obviously to improve previous results. There have been improvements in the reliability of the hardware, which was a particular problem in the early years. 1° Further success is likely to be achieved by seeing patients at an early stage in their disease, by understanding that many patients have an underlying rectal sensory abnormality, by using advanced physiological measurements to select patients, and by finding a solution to the impaired rectal evacuation that can mar the result in up to 25% of patients. Meanwhile affected individuals need to be made aware of the existence of techniques that avoid a permanent stoma. References 1 T h o m a s T M , Egan M, Walgrave A, Meade T W , The prevalence of faecal and double incontinence. Community Med 1984; 6: 216-20. 2 Pena A, de Vries PA. Posterior saggital anoectoplasty: important technical considerations a n d new applications. J Paed Surg 1982; 17: 796 809. 3 Malone PS, Ransley PG, Kiely EM. Preliminary report: the antegrade continence enema. Lancet 1990; 3 3 6 : 1 2 1 7 - 1 8 . 4 Williams NS, Hughes SF, Smchfield B. Continent colonic conduit for rectal evacuation in severe constipation. Lancet 1994; 343: 1321-24. 5 Sultan AH, K a m m MA, H u d s o n CN, Bartram CI. T h i r d degree obstetric anal sphincter tears: risk factors a n d outcome of primary repair. BMJ 1994; 3 0 8 : 8 8 7 - 9 1 . 6 MacArthur C, Bick DE, Keighley MRB. Faecal incontinence after childbirth. BrJ Obstet Gynaecol 1997; 104: 46-50. 7 Williams NS, Patel J, George BD, Hallan RI, Watkins ES. Development of an electrically stimulated neoanal sphincter. Lancet 1991; 3 3 8 : 1 1 6 6 - 6 9 . 8 Baeten CG, Geerdes BP, Adang EM, et al. Anal dynamic graciloplasty in the treatment of intractable fecal incontinence. N Engl JMed 1995; 332: 1600-05. 9 Lehur PA, Micho~: F, Denis P, et al. Results of artificial sphincter in severe anal incontinence: report of 14 consecutive implantations. Dis Colon Rectum 1996; 39: 1352-55. 10 M a n d e r BJ, Wexner SD, Keighley MRB, et al. The electrically stimulated gracilis neoanal sphincter: preliminary results of a multicentre trial. BrJ Surg 1997; 84(Suppl 1): 39.
Surgery • Vol 353 • April ° 1999