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| 번호 | 제목 | 등록일 | 조회수 |
|---|---|---|---|
| 85 | Excision of Anal Fistula With Closure of the Internal Opening [2002년 12월 DCR] | 2011-11-17 | 3934 |
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Functional and Manometric Results
Ulla-Maria Gustafsson, M.D., Wilhelm Graf, Ph.D.
From the Department of Surgery, University Hospital, Uppsala, Sweden
PURPOSE: The aim of this study was to evaluate the results concerning recurrence and continence after sphincter-saving surgery for fistula-in-ano.
METHODS: Forty-two patients with anal fistula traversing the sphincter were operated on with fistula excision and closure of the internal opening. Patients answered a questionnaire concerning bowel habits and continence before and 3 and 12 months after surgery. A subgroup of 19 patients were also examined with anal manometry.
RESULTS: Twenty-three (55 percent) patients healed primarily after surgery and a further 10 (24 percent) after one reoperation, whereas 7 (17 percent) required 2 to 4 reoperations until healed. In two patients therapy was changed to cutting seton treatment. After 1 year 21 of 36 (58 percent) patients reported improved or unaffected continence and 11 (31 percent) reported a slight and 4 (11 percent) a major decrease in continence. Detailed data on preoperative continence were missing for five patients, and one had a colostomy at late follow-up. Anal manometry showed a significant decrease in resting pressure after three months and a further decrease in both resting and squeeze pressures after one year.
CONCLUSION: Surgery for anal fistula with excision and advancement flap has a fairly high initial recurrence rate but a good final success rate. A decrease in continence is seen also after this kind of surgery for anal fistula. Manometric results suggest that this is associated with an impaired internal anal sphincter function.
The aim of treatment for fistula-in-ano is to permanently eliminate abscess formation and achieve healing with preservation of anal function and continence. Traditional surgical treatment of high
transsphincteric anal fistula with a staged seton procedure or laying open results in impaired continence in a high proportion of patients. To avoid this, sphincter-saving surgery has been developed, and core fistulectomy with closure of the internal opening with an advancement flap technique is increasingly used. The primary aim of this study was to evaluate the clinical results after sphincter-saving surgery for anal
fistula with regard to recurrence rate and continence. A secondary aim was to study the effect on sphincter function using anal manometry. Surgical Procedure
The patients were operated on in the jackknife position in general or regional anesthesia. All patients
had a routine colonic washout bowel preparation preoperatively. Thirty-six patients received preoperative single-dose antibiotic prophylaxis, and 12 of them also had postoperative antibiotic treatment. Six patients did not have any antibiotics. The operation commenced with injection of hydrogen peroxide in the external opening with an anal retractor (Pratt or Parks retractor) inserted to visualize the anal canal. After identification of the internal opening, the height of the fistula was assessed by gently probing the primary tract. Core excision of the primary tract into the anal canal was performed. Extensions were either excised or curetted depending on their location in relation to the sphincters and the bowel wall. Horseshoe extensions were partially laid open. Closure of the internal opening was done by suturing the internal sphincter and mucosal layers in the first eight cases, but subsequently by an advancement flap technique. The flap comprised mucosa, submucosa, and a partial thickness of the rectal wall or internal sphincter. The flap was always raised proximally and advanced distally. The external wound was left open and managed postoperatively with daily irrigation. The patients had stool softeners, but otherwise ordinary diet from the first postoperative day. They were followed up 1 to 4 months after surgery (median, 2 months for early follow-up) and after 9 to 43 months (median, 21 months for late follow-up). In four cases late follow-up was replaced by a postal inquiry concerning bowel function and recurrence of fistula symptoms or further treatment. Two patients, who were healed at early follow-up, were lost to late follow-up. DISCUSSION
Seton treatment for high or complicated anal fistula is associated with a recurrence rate of 2 to 15 %. With the sphincter-saving advancement flap technique recurrence rates have varied between 1 and 16 percent in three larger studies and between 9 and 25 percent in smaller ones. In this study the primary healing rate was 55 and 80 percent after one or two surgical procedures, respectively. The final success rate was 95 percent. Primary healing thus occurred in 55 percent, whereas 45 percent required at least two procedures to cure the fistula. Closure of the internal opening by sutures was abandoned after the initial eight cases because of the high rate of nonhealing. Because repeated procedures might lead to impaired continence, there is an urgent need to find methods which may promote primary healing. Therefore, we are currently performing a randomized, controlled study exploring the possible benefit of “adjuvant” collagen-gentamicin application. Other authors have found an increased recurrence rate with increasing complexity of the fistula, such as horseshoe extensions or suprasphincteric or extrasphincteric fistula. An overlooked extension may thus theoretically be the reason for some of the failures. In this study we could not demonstrate this association, but found an increased recurrence rate associated with female gender. Interestingly, postoperative antibiotic
treatment was associated with a reduced recurrence rate. The lower recurrence rate in males cannot be explained by less complex fistulas; however, males had higher rates of horseshoe and other extensions and also a higher rate of previous fistula surgery. There was no difference in postoperative antibiotic treatment between males and females. In other studies of fistula surgery with advancement flap, the use of antibiotics has varied from only prophylaxis to continued postoperative treatment. Incontinence is difficult to evaluate, but several studies have shown continence disturbances in 44 to
67 percent of patients treated with cutting seton or two-stage fistulotomy, although Pearl et al.found only 3 percent incontinence after staged fistulotomy for complicated anorectal fistulas. Most authors have not found any incontinence symptoms after advancement flap procedures, but Aguilar al.reported 10 percent with minor symptoms and Schouten et al. 35 percent with decreased continence. According to the incontinence score 22 percent of our patients experienced improved continence postoperatively, which may be attributed to cessation of fistula symptoms. A slight decrease in continence was reported by 33 percent and occurred mainly between early and late follow-up. In some cases this may be because of further operations. Two of the four patients who developed a more severe decrease in continence did so after reoperations with partial or total division of the internal sphincter. Except for continence and pruritus ani the bowel function questionnaire did not show any change in
symptoms over time. Nor could any difference be demonstrated in impact on social life or general well-being. This may be because of small numbers but also because of the fact that the questionnaire is principally constructed for assessing patients with incontinence or constipation. It may be too blunt an instrument for demonstrating symptom differences in anal fistula patients. There is no special symptom- assessment or quality-of-life instrument developed for this group of patients. Sailer et al. tried the Gastrointestinal Quality of Life Index on 325 patients with different benign anorectal disorders, including 22 with anal fistula and could not find any difference in quality of life in fistula patients compared with controls. Manometric results showed a significant decrease in resting pressure at the early follow-up, but not in
squeeze pressure, indicating involvement of the internal sphincter. This is supported by the fact that the difference between squeeze and resting pressures, used as a measure of external sphincter function, did not change significantly. Thus the decrease in continence seems to be associated to an impaired internal sphincter function. Because the flap includes part of the internal sphincter, the operation, and especially repeated procedures, may weaken the sphincter and cause a decrease in continence. This complication may be avoided if the flap is raised well above the internal sphincter. The anal dilation during surgery using a self-retracting anal retractor is another possible cause. In some cases there also seems to be a decrease with time without further operations. The lack of correlation between major continence deterioration and nonhealing may be because of the relatively small number of patients. Impaired continence may also be because of scarring in the anal canal. Traditional treatment of sphincter-traversing anal fistulas with laying open or seton treatment has concentrated mainly on preserving as much external sphincter muscle as possible, with the goal of minimizing continence disturbance, whereas preservation of the internal sphincter has been considered less important. The rate of continence disturbance after laying open of intersphincteric fistula has been 13 to 38 percent, which indicates that preserving the internal sphincter muscle is important to minimize incontinence. This recommendation is further supported by our finding of severe incontinence after
internal sphincterotomy in two patients. Curettage instead of coring out of the primary fistula tract would possibly lessen the risk of sphincter damage, but may increase the risk for inadequate drainage and subsequent nonhealing. We found that surgery with excision and advancement
flap repair for sphincter-traversing anal fistula has a higher recurrence rate than traditional staged seton procedure or laying open, but a high final success rate. Postoperative antibiotic treatment and male gender was associated with primary healing. A decrease in continence, associated with an impaired internal sphincter function, is seen also after this type of fistula surgery. Continence disturbances were more frequent in patients with primary nonhealing, which underlines the need for developing methods to increase the primary healing rate. |
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