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| 번호 | 제목 | 등록일 | 조회수 |
|---|---|---|---|
| 71 | Artificial Anal Sphincter [2002년 9월 DCR] | 2011-11-17 | 3718 |
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Complications and Functional Results of a Large Personal Series
Jose M. Devesa, M.D., Antonio Rey, M.D., Pedro L. Hervas, M.D.,Kamal S. Halawa, M.D., Itziar Larran˜aga, M.D., Laura Svidler, M.D.,Victor Abraira, Ph.D., Alfonso Muriel, Ph.D.
From the Divisions of Colon and Rectal Surgery and Medical Biostatistics, University Hospital Ramo´n y
Cajal, Madrid, Spain PURPOSE: This study was undertaken to evaluate the technique of artificial sphincter for fecal incontinence, with its complications and risk factors, the functional results, and which variables derived from demographic data, preoperative studies, device characteristics, technical details, perioperative
findings, and complications could influence the outcome. METHODS: The Acticon Neosphincter® was implanted in 53 patients (35 females), median age 46 years, with total anal incontinence not amenable to sphincter repair or after failed sphincteroplasty. In females with associated rectocele, this was synchronously corrected. Six (11 percent) patients already had a colostomy, but no proximal stoma was constructed at the time of implantation. Causes of incontinence were congenital, 13; iatrogenic, 13; obstetric, 10; neurogenic, 9; trauma, 4; idiopathic, 2; and perineal colostomy, 2. Physiologic testing before and after the operation and preoperative endosonography were done when they were available. Quality of life was assessed in 25 patients. Mean follow-up was 26.5 (range, 7–55) months. RESULTS: Perioperative events occurred in 14 (26 percent) patients: abnormal bleeding, 7; vaginal perforation, 4; rectal perforation without apparent contamination, 2; and unobserved urethral perforation, 1. Early complications were mainly related to sepsis in 8 (15 percent) patients and wound complication in 8 (15 percent). Sepsis could not be statistically associated with any of the variables studied here. Wound separation was associated with fibrosis (P = 0.003) and tension of the wound (P = 0.001). Late complications were: cuff and/or pump erosion, 9 (18 percent) patients; infection, 3 (6 %); impaction, 11 (22 percent); pain, 4 (8 percent); and mechanical failures, 2 (4 percent). None of those complications showed a statistical association with any of the variables studied here. There were 10 (19 percent) definitive explants caused by septic or skin complications. Only 26 (60 percent) of 43 patients with the device in action use the pump (patients’ decision). Normal continence was achieved in 65 percent of patients and continence to solid stool in 98 percent. The Cleveland Clinic score of incontinence (0–20, maximal incontinence) changed from 17 +/- 3 preoperatively to 4 +/- 3 postoperatively (P = 0.000). An early complication of the perianal wound influenced the functional results: postimplant score > 4 vs. =/< 4 (P = 0.009). Resting and squeeze pressures changed significantly after activation (P = 0.000). Quality of life measured in four subscales changed significantly in all the subscales (P = 0.000). CONCLUSIONS: The artificial anal sphincter restores continence to solid stool in almost all severely incontinent patients, two-thirds of whom achieve practically normal continence. Quality of life improves
significantly. Infection and skin erosion are the cause of the majority of explants. No predictable factors of functional success could be found in this study. Successful perianal implantation of an artificial sphincter was first published in 1987 by Christiansen
et al., but a specially designed bowel sphincter (Acticon®; American Medical Systems, Minneapolis, MN) was not available until 1996. Since then, an increasing interest with this technique has developed for treating severe anal incontinence not amenable to sphincter repair. This is a prospective, nonrandomized study of a personal series from 53 consecutive patients who had
variable degrees of total anal incontinence of various causes and underwent implantation of the artificial bowel sphincter when sphincter repair was not possible or had failed. We aimed to analyze the technique with its complications and their risk factors, as well as the results and a series of variables, which could have an influence on the functional outcome. To the best of our knowledge, this type of study has not yet been reported. DISCUSSION
Our study corroborates that the Acticon Neosphincter ® is an efficient and promising method of treating
patients with total anal incontinence caused by congenital malformations and irreparable or denervated sphincters, achieving normal continence in two-thirds of patients and complete continence to solid stool in almost 100 percent. Quality-of-life scores also improved significantly. Case selection is a critical aspect for success. In our series, the two patients with a perineal colostomy
warrant comment because there are no previous reports with that indication. Although the functional result was poor in one patient and the second patient still has a diverting stoma, the procedure was technically straightforward, and the local conditions were very similar to those found in patients with congenital malformation. None of those patients had received radiotherapy, which should contraindicate the implantation of prostheses if the tissues are damaged. We believe that this new indication deserves attention in the future. Another point of controversy should be at which degree of incontinence this technique is indicated. So far, selection of candidates has been very strict according to American Medical Systems recommendations following its continence grading scale. However, there are patients with a lesser degree of incontinence, unsuccessfully managed with medical treatment and not amenable to simple surgical repair, in whom incontinence has an impact on their quality of life. Although the device is still expensive, the cost of other more conservative measures also has to be considered because the technique is not a major surgical procedure; postoperative course is usually simple; complications can be safely managed with negligible life risk; and it does not have a cosmetic impact. All these pros and cons should be discussed extensively with the patient after complete preoperative assessment. Although there are no welldefined limits of age, it seems reasonable to wait until puberty in young patients and to not perform the implantation in old patients with very limited activities and a short life expectancy. Also, little-motivated patients should not be candidates. Surgeons’ experience in dealing with anal incontinence is a crucial point for achieving success. Some
surgical details merit comment: ● The use of a single preanal transverse incision is recommended and formally indicated in females
with a thin perineal body. Any anatomic rectocele should be synchronously corrected; otherwise the implant would act as a mechanical obstacle leading to an outlet subobstruction. As for the rest of the patients, now we are not so strict and we prefer any scar-free access, with double incision if lateral to the anus. Early skin dehiscence, thus predisposing to contamination and infection, was significantly higher when the incisions were performed through fibrous tissue. A very small posterior incision might be helpful in patients with thick buttocks and a deep anus, if it is difficult to surround the rectum from the anterior incision. The wounds should be closed in the same direction as they were performed. Frequently after the placement of the device, the wound adopts a different shape. In those cases in which we performed a pyloroplasty-like closure, tension in some part of the wound was higher and predisposed to early skin dehiscence. ● The cuff should be placed at least 3 cm deep from its lower border. If the placement is more
superficial, the risk of erosion may be very high. Downward displacement of the cuff might occur in patients with continuous straining at defecation. To avoid this, a modification of the cuff design, which would include some anchoring of small loops on its upper border, has been suggested to the manufacturer. The cuff should not lie in direct contact with either the vaginal or rectal wall; thus a pillow of muscular, adipose, or fibrous tissue (if the only one available) was created before implanting. This would diminish the risk of visceral erosion. ● Selection of the device is also very important. An 81- to 90-cm H2O pressure-regulating balloon seems to be enough for the majority of patients. Also, the 2-cm-wide cuff creates a sufficient length of functional anal canal, whereas the 2.9-cm cuff could compromise the recommended distance between its lower border and the skin, and a deeper, sometimes difficult, dissection should be necessary. However, in a young male who maintained incontinence, the 2-cm cuff was changed to 2.9 cm with achievement of continence without changing the balloon pressure and cuff length. Cuff length has its
own impact on the continence status, although it has not been statistically reflected in our study. Surgeons’ decisions are subjective and may be mistaken, as was clearly reflected in one female who had continuous straining at defecation and needed daily enemas for evacuation; the 8-cm cuff was changed to 12 cm, maintaining normal continence without any more defecation difficulty. Our view of the matter is that, when there is a doubt between two cuff lengths, we now recommend the shorter for patients with soft or frequent episodes of liquid stool and the longer for those with normal or hard stool. ●We do not consider that a diverting stoma is routinely necessary because it has not been demonstrated that the risk of infection is less, and morbidity associated with creation and takedown of a stoma is not infrequent. In our series, we could not show any statistical association between colostomy vs. noncolostomy and complications, although the number of patients with colostomy is too small.
Early complications were mainly related to wound dehiscence and infection. As has already been mentioned, wound dehiscence was significantly associated with fibrosis and tension. This has led us to select the place of the perianal incision through the best possible site rather than to perform always a single transverse incision or two laterals. A wound seroma is likely to develop if hemostasis is not good, and it can become contaminated, as happened in one of our patients who was successfully treated with antibiotics, although this could have been the exception. In some of the last patients of our series, we injected a solution of epinephrine 1:300 subcutaneously before starting dissection, both around the anus and in the area that joins the suprapubic and perianal incisions. No seroma developed in any of those patients; thus it might be worthwhile to do it routinely.
Infection is the most fearsome complication. In all of our patients in whom infection was clinically
evident, removal of a part or the whole system was eventually necessary, despite exhaustive local care and culture-guided antibiotic treatment. Although other authors reported a successful conservative management of infections, they did not comment on the type of organisms recovered and antibiotic regimen, length of treatment, and length of follow-up after apparent cure. From our experience, we now recommend explanting the affected part of the device without delay once the infection becomes evident, thus avoiding the risk of infection spread and a prolonged, costly, and useless treatment. If a further reimplant is considered, it is advisable to wait several months; otherwise the risk of reinfection could be very high. In the meantime, a diverting stoma might be necessary. In most of our patients, infection could have been secondary to skin dehiscence and not related to intraoperative contamination. Although the number of cases was small, our experience showed us that perforation of the vagina or rectum without apparent contamination would not necessarily mean stopping the procedure. However, this is a controversial attitude, and the surgeon must decide about this in each particular circumstance. Optimal regimen of antibiotic prophylaxis, whether or not followed by treatment, is an important matter for avoiding infection. Although our infection rate of 13 percent was reasonable, in our last 4 patients we started to follow the recommendations given by a specialist who was consulted by American Medical Systems, therefore changing our initial protocol of metronidazole plus amoxicillin-clavulanic acid to vancomycin plus piperacillin/tazobactam. It is important to remark that infections were always caused by multiple bacteria with the E. coli always present. Routine antibiotic treatment for several days might not be necessary unless there is a perioperative risk factor of infection, the wound disrupts, or the patient develops persistent fever despite an apparently normal aspect of the wounds. Although in this study we could not find any factor statistically associated with infection, it is obvious that any factors that contribute to wound contamination during the procedure (e.g., inadequate mechanical preparation, perforation of the rectum or vagina, or a difficult performance), and skin dehiscence or decubitus, are clear risk factors for infection. Cuff and pump erosions were the most frequent late complications. Erosion may be caused by infection,
pressure on the tissue, improper cuff sizing and balloon selection, tissue damage, and component misplacement. In this series, skin erosion could not be associated with preexisting fibrosis, different closure of the wound or tension at closure, postoperative soiling, or straining. However, a too-superficial cuff and continuous straining at defecation are risk factors for erosion; therefore, technical performance of the procedure and cuff size selection might be critical. Once erosion develops, if infection is not already present, immediate revisionary surgery and prolonged antibiotic treatment can avoid explantation in a percentage of patients, as happened in our series. Primary late infection without apparent basis has been reported by other authors. In our series, this
could have happened in three patients, but all were seen when the pus was already draining, making it impossible to know whether there was first a skin erosion that caused the infection. However, one of the patients had had fever of unknown origin in the early postoperative period, and late infection could have been a delayed manifestation of a subclinical early infection. Both fecal impaction and perianal pain are functional device-related complications, which might cause variable degrees of discomfort, but only one of our patients wished to have the device removed for
these reasons. Although fecal impaction can be avoided with medication or changing the cuff to a longer size if necessary, perianal pain has no recognizable cause, thus making difficult its avoidance and management. However, pain is usually well tolerated compared with incontinence and seems to diminish as time goes by. So far, mechanical failures of the device were only anecdotal, but longer follow-up is needed before establishing the long-term quality of the product. A question emerges: should young patients be advised
against participating in violent sports and riding bicycles? In our series, revisionary surgery was needed in 60 percent of patients with complications, or in 26 percent of all patients, with an explant rate of 19 percent. This is less than that reported by Christiansen et al.,but those authors had a longer follow-up.
Functional results were excellent in a significant group of patients, with marked improvement of continence and quality-of-life status in all the rest except in one patient with a perineal colostomy. However, that patient had a 2-cm-wide and 13-cm-long cuff, which could be changed to a 2.9-cm-wide and shorter cuff before being considered as a definitive failure. Curiously, a significant number of patients did not use the pump because they were able to evacuate with the cuff activated without difficulty, while others felt happy with their continence status with the cuff deactivated. The latter group consisted only of females who felt that the management of the pump was unpleasant or were less motivated and fearful of damaging the mechanism. We ourselves sometimes found it difficult to squeeze the pump in those females with thick labia and a deep pump. From our current analysis with the number of patients involved in the study, there is no way to predict a functional result based on patient demographics and cuff length, but, from another perspective, this was an important finding because
it means that every incontinent patient with the inclusion criteria accepted here can benefit from this technique. Soiling was not related to any of those variables, with the exception of the number of milliliters filling the cuff. We found that, when the cuff is filled with more than 3 ml, the likelihood of soiling is higher, which probably indicates a looser cuff, also suggested by the fact that none of those patients developed fecal impaction. Significant improvement in the resting pressure is a logical finding, and it correlates with improvement
in continence and some subscales of quality of life. However, there is no clear reason for a significant improvement in the squeeze pressure, although the effect of reefing with the available muscle performed in some of the patients could explain at least part of these results. (An individualized statistical analysis of that was not performed.) Coincidentally with Vaizey et al.,6 we did not find a significant change in anal or rectal sensation although some patients improved. |
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